PGP.com is not the only source for versions of PGP, however. What follows below is a summary of the various versions of PGP that are available on the Net and where they can be found.

Versions of PGP

Following NAI's sale of PGP to PGP Corporation, the latest official build of PGP is PGP 9.0, from PGP Corp. (PGP.com). PGP 9.0 Desktop Professional and PGP 9.0 Desktop Home include PGPmail, PGPdisk, and several email plug-ins. PGP 9.0 Desktop Professional also includes PGP Whole Disk. You can purchase PGP 9.0 Desktop Professional and PGP 9.0 Desktop Home from the PGP.com Store or from Phil Zimmerman. A PGP 9.0 Freeware version (which includes only PGPmail) is also available as a trial version of PGP 9.0 Desktop Home.

PGP Corp. isn't the only source for the many PGP versions you can find on the Net, however. PGP has a long history of "unofficial" builds, though many of those "unofficial" non-NAI or non-PGP.com versions of PGP have ultimately been built in one way or another from official NAI PGP source code. 

For simplicity's sake, we will distinguish between PGP Corp., NAI, and Other versions of PGP:

	Version	$$$	Features & Components	Other Notes
P G P   C O R P	PGP Freeware		Core functionality, but lacking certain extra components (e.g., PGPdisk & email plug-ins).	For personal use only. License is perpetual. PGP 9.0 Freeware is the equivalent of PGP 9.0 Desktop Home trial version.
	PGP   Desktop Professional	$$$	Core functionality, complete extra components  (incl. PGP Whole Disk,  PGPdisk, & email plug-ins), as well as features for corporate deployment.	For commercial use. Licenses can be annual or perpetual. Previously known as PGP Workgroup Desktop, PGP Desktop, PGP Corporate Desktop,  PGP Desktop Security, and PGP Business Security.
	PGP  Desktop Home	$$$	Core functionality, complete extra components (incl. PGPdisk & email plug-ins), but without features for corporate deployment.	For commercial use. License is perpetual. Previously known as PGP Personal Desktop, PGP Personal, PGP Personal Security and PGP Personal Privacy.
N A I	PGP Freeware		Core functionality, but lacking certain extra components (e.g., PGPdisk & PGPfire).	For personal use only. Last version from NAI was 7.0.3, which is still available from PGPi. Slightly older version (6.5.8) still available from MIT.
	PGP Desktop Security	$$$	Core functionality, complete extra components  (incl. PGPdisk, PGPnet, & PGPfire), as well as features for corporate deployment.	For commercial use. Last version by NAI was 7.1.1. Known as PGP Corporate Desktop starting with PGP 7.1. Previously known as PGP Business Security.
	PGP Personal Security	$$$	Core functionality, complete extra components (incl. PGPdisk, PGPnet, & PGPfire), but without features for corporate deployment.	For commercial use. Last version from NAI was 7.0.3. Previously known as PGP Personal Privacy until PGP 7.0..
O T H E R	PGP CKT		Core functionality, same components as PGP Desktop Security (e.g., PGPdisk, et al), as well as additional enhancements (e.g., support for very large keys).	Compiled from PGP Intl source code and enhanced by Imad R. Faiad. Imad continues to release new builds (the latest is 6.5.8ckt build 08). See "About the PGP 6.5.8ckt Builds" below for a more complete description of Imad's enhancements in the CKT builds.
	PGPi		Core functionality, but lacking certain extra components (e.g., PGPdisk & PGPfire).	Independently compiled from PGP Intl source code, which was originally scanned from NAI source code. No PGPi versions after PGP 6.5.1, as the NAI versions became legally exportable.

PGP Corporation has been introducing a wide range of enterprise products over the last few years, which are not listed above. For a summary and guide to the plethora of PGP products available from PGP Corp., see THIS page. See also PGP.com's Desktop FeatureComparison chart for a summary of the features of various versions of PGP Desktop, which is the latest incarnation of the traditional PGP client software.

The chart above presents a somewhat simplified picture of the various PGP versions available on the Net. For a more complete account of PGP versions, see RJ Marquette's PGP Interactions Page and Tom McCune's PGP Questions & Answers page. 

Sources for PGP

PGP commercial and freeware versions are available from several "official" sources:

• PGP Corporation (PGP.com)
• The MIT Distribution Center for PGP (MIT)
• The International PGP Page (PGPi)

Those several sources carry various different versions and builds of PGP:

• For Desktop Professional, Desktop Home, & Freeware versions of PGP at "official" locations, 
  see the "Official" Sources for PGP section below.
   
• For CKT versions of PGP, check the PGP CKT Builds section.
   
• For the older PGPi versions, proceed directly to PGP International's home page or ftp site.
   
• Various versions of PGP can also be found in a number of other locations, which are listed 
  in the Other Sources for PGP section.

"Official" Sources for Other Versions of PGP

Below is a table detailing the various versions of PGP that are available from "official" sources:

Version	$$$	PGPdisk	WholeDisk	PGPnet	PGPfire	Source	URL
9.0.x Workgroup	$$$	X	X	---	---	PGP.com	http://www.pgp.com/
9.0.x Personal	$$$	X	---	---	---	PGP.com	http://www.pgp.com/
9.0.x Freeware		---	---	---	---	PGP.com	http://www.pgp.com/
8.1.x Workgroup	$$$	X	---	---	---	PGP.com	---
8.1.x Workgroup	$$$	X	---	---	---	PGP.com	---
8.0.x Workgroup	$$$	X	---	---	---	PGP.com	---
8.0.x Personal	$$$	X	---	---	---	PGP.com	---
8.0.x Freeware		---	---	---	---	PGP.com	---
7.1.x Desktop	$$$	X	---	X	X	n/a	---
7.0.x Desktop	$$$	X	---	X	X	n/a	---
7.0.x Personal	$$$	X	---	X	X	n/a	---
7.0.x Freeware		---	---	X	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
7.0.x Freeware		---	---	X	---	PGPi	http://www.pgpi.org/
6.5.x Desktop		X	---	X	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
6.5.x Freeware		---	---	X	---	MIT	http://web.mit.edu/network/pgp.html
6.5.x Freeware		---	---	X	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
6.5.x Freeware		---	---	X	---	PGPi	http://www.pgpi.org/
6.5.x Intl		---	---	X	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
6.5.x Intl		---	---	X	---	PGPi	http://www.pgpi.org/
6.0.2 Intl		X	---	---	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
6.0.2 Intl		X	---	---	---	PGPi	http://www.pgpi.org/
pre-6.0.x Intl		---	---	---	---	PGPi (ftp)	ftp://ftp.pgpi.org/pub/pgp/
pre-6.0.x Intl		---	---	---	---	PGPi	http://www.pgpi.org/
2.6.2 Freeware		---	---	---	---	MIT	http://web.mit.edu/network/pgp.html

PGP 9.0 Commercial Versions

On May 10, 2005,  PGP Corp. released PGP 9.0 for Windows and the Mac (see the news section above). The new PGP 9.0 Desktop Professional and Desktop Home versions can be purchased from:

• http://www.pgp.com/

If you're interested in using add-on components like PGPdisk or email plug-ins, then you'll need to obtain one of the following:

• the most recent PGP 9.0 Desktop Professional or Desktop Home
• one of the older versions of PGP Workgroup Desktop or PGP Personal Desktop
• one of Imad's PGP CKT builds.

Note that PGP Whole Disk is included only in PGP 9.0 Desktop Professional. There are several places to go for these various versions of PGP.

• The PGP.com Store is selling PGP 9.0 Desktop Professional, but this new version does not have PGPnet or PGPfire, which were last seen in the old NAI PGP 7.x Corporate Desktop versions of PGP. International PGP users should visit the Intellect PGP EMEA page for information about ordering PGP 8.0. The last Corporate Desktop version released by NAI (which did include PGPnet and PGPfire) was PGP Corporate Desktop 7.1.1, but you can no longer get it through the PGP.com store. 
   
• The PGP.com Store is offering PGP 9.0 Desktop Home, but this new version does not have PGPnet or PGPfire, which were last seen in the old NAI PGP 7.x Personal Security versions of PGP. The last Personal Security version released by NAI (which did include PGPnet and PGPfire) was PGP Personal Security 7.0.3 and is no longer available. 
   
• Imad's latest CKT build is PGP 6.5.8ckt build 08 and can be downloaded for from Imad's PGP Page. The recent CKT builds include older versions of PGPdisk and PGPnet.
   
• You can also purchase commercial versions of PGP 9.0 from Phil Zimmerman's home page. The new PGP 8.0 Workgroup Desktop and Personal Desktop include PGPmail as well as PGPdisk and email plug-ins. (PGPfire and PGPvpn have been dropped from the "official" versions of PGP -- those products are retained by NAI.)

See the next section, PGP Components, for more information on the several add-on components included with PGP Workgroup Desktop and Personal Desktop. And see also the news section above for details of changes in the new PGP 8.0 from the new PGP Corporation.

PGP 9.0 Freeware

If you're only interested in using PGP to encrypt and sign email messages and individual files that you exchange with others, then any of the more recent PGP Freeware versions will work for you. PGP Corp. currently has no product called "PGP Freeware" listed on its web site, however, the PGP Desktop Home trial version is effectively the same product as what was known as PGP Freeware. Recall that the old PGP 8.0 Personal turned into PGP Freeware, which included the limited freeware feature set, if the user failed to register the product with a valid license key. PGP Desktop Home trial version functions the same way, except that PGP Corp. does not called the feature-restricted version "PGP Freeware." This web page refers to "PGP 9.0 Freeware" only for the sake of conistency and clarity.

PGP 9.0 Freeware includes only PGPmail, not PGPdisk or PGP Whole Disk. Notably, PGP 9.0 Freeware also does not include any email plug-ins for email clients such as Outlook, Outlook Express, or Eudora. With PGP 9.0 Freeware you'll have to use the Current Window function from PGPtray to encrypt and sign email. To get the PGPdisk and the plug-ins, you must upgrade to PGP 9.0 Desktop Professional and PGP 9.0 Desktop Home. To get PGP Whole Disk, you'll need PGP Desktop Professional.

For information on installing and using the older PGP 8.0 Freeware, see THIS page. Please note that versions of PGP may be free only for personal,non-commercial, or educational use.

Following the transfer of ownership of PGP from NAI to PGP Corp. (see the news section above for details), the old link to PGP Freeware 7.0.3 on the PGP.com web site isn't working.  You can still download PGP Freeware 7.0.3 (the last freeware version released by NAI) from the International PGP Page, however.

PGP Command Line Versions

The more recent Windows versions of PGP from NAI and PGP.com do not include an integrated command line version of PGP. Rather, a separate PGP Command Line package was produced for the NAI versions. PGP Corp. released its own PGP Command Line in June of 2004. See the following page for more information:

• http://www.pgp.com/products/commandline/index.html

There are several versions of PGP Command Line still available. In its sale of PGP to PGP Corporation, NAI retained the rights to the most recent version of PGP Command Line, which is now named McAfee E-Business Server:

McAfee E-Business Server
http://www.networkassociates.com/us/products/mcafee/encryption/ebusiness_server.htm

The older PGP Command Line 6.5.8 is still available from MIT and PGP International:

PGP Command Line 6.5.8
http://web.mit.edu/network/pgp.html
http://www.pgpi.org/products/pgp/versions/freeware/win32/6.5.8/
ftp://ftp.pgpi.org/pub/pgp/6.5/6.5.8/

If you're interested in using PGP from a command line, you might also be interested in the many PGP 2.6.x versions that are still available -- see below for more info.

PGP 9.0 Licensing

Commercial versions of the new PGP 9.0 use a licensing scheme that you should be aware of. This new licensing scheme involves an online product activation process through which users activate PGP with a License Number (though you can get a License Authorization to copy and paste into the appropriate license box and avoid the online activation). See PGP.com's License Engine FAQ and License Engine Troubleshooting pages for more information.

One other noteworthy feature of this new licensing scheme is that the download packages for the PGP 9.0 Desktop Home trial version and Freeware are one-and-the-same . If you don't purchase PGP 9.0 Desktop Home and activate online, the product will effectively function as PGP 9.0 Freeware (which does not include PGPdisk or any email plug-ins). Once you purchase a license and activate, the additional components of PGP 8.0 Desktop Home will become functional.

If you are having problems downloading or licensing PGP 9.0, see PGP's Online Support Services. 

PGP Keys & Algorithms

For information on the various algorithms, key types, and key sizes supported by the many versions of PGP that have been released over the past decade, see this large set of PGP Compatibility Tables. PGP.com has its Technical Specifications pages for PGP 9.0 Desktop Professional and PGP Desktop Home.

PGP Whole Disk is a new feature included pnly with PGP 9.0 Desktop Professional, not any previous version of PGP or even PGP 9.0 Desktop Home. PGP Whole Disk allows for the entire contents of a physical hard drive to be encrypted, as opposed to portions of drives set up as "virtual drives" (ala the older PGPdisk).

PGPdisk is included with PGP Desktop Professional and PGP Desktop Home -- the most recent versions -- as well the older PGP Workgroup Desktop, PGP Corporate Desktop, PGP Desktop Security, PGP Personal Desktop, PGP Personal, PGP Personal Security, and PGP Personal Privacy versions 6.0.x and higher (incl. 6.5.x , 7.x, and 8.0.x). PGP CKT versions 6.0.x and higher also contain PGPdisk. PGPdisk is not included with PGP Freeware or PGPi versions (except PGP 6.0.2i, which does include it). PGPdisk is a utility that allows you to encrypt files on your hard drive and store them in large, encrypted "container files" that can be mounted as "virtual drives," making encryption and decryption of files a snap. For a short tour of PGPdisk (with screenshots), click HERE.

Unlike PGPnet or PGPfire, PGPdisk from PGP 6.x, PGP 7.x, PGP 8.x, and PGP 9.0 is compatible with most versions of Windows. To use PGPdisk on Windows XP, though,  you'll have to obtain a copy of the newer PGP 9.0 Desktop Home or Desktop Professional, or the slightly older PGP 8.0 Desktop or Personal, all of which includes full Windows XP compatibility. You can also use the older PGP 7.1.1 Corporate Desktop or PGP 6.5.8ckt build 08 (or later), as PGPdisk from earlier versions of PGP will not work on Windows XP. (For Windows 2000, you should get at least PGP 6.5.2 Desktop Security or Imad's latest PGP 6.5.8ckt build, though PGPdisk from earlier PGP versions appears to work on Windows 2000.) 

PGPdisk has gone through some changes from the earliest standalone version (PGPdisk 1.0, which was later incorporated into PGP 6.0.0) through the latest versions found in PGP 7.x:

• PGP 6.0.2, PGP 6.5.x, PGP 7.x, and PGP 8.0 will insist on converting PGPdisk volumes from PGPdisk 1.0 or 
  PGP 6.0.0 in order to correct a security bug that was discovered in those early releases of PGPdisk. Once converted,
  those volumes will be unreadable by PGPdisk 1.0 or PGP 6.0.0.
   
• PGP 7.x and PGP 8.0 will insist on converting PGPdisk volumes from PGP 6.0.2 or PGP 6.5.x to a newer format.
  Once converted, those volumes will be unreadable by earlier versions of PGPdisk.
   
• PGPdisk from PGP 7.x and PGP 8.0 includes a number of new features, including the ability to use the Twofish-256 
  algorithm to encrypt volumes (all previous versions of PGPdisk are limited to CAST5-128).
   
• PGPdisk from PGP 8.0.2 includes the ability to use the AES-256 algorithm to encrypt volumes (all previous versions 
  of PGPdisk are limited to Twofish-256 and/or CAST5-128).

If you're interested in creating and using virtual encrypted drives, there are several third-party OTFE (on-the-fly-encryption) programs that are viable alternatives to PGPdisk. For Windows 9x/Me you could use Scramdisk or E4M. E4M can also be used on Windows NT 4.0. For OTFE programs known to be compatible with Windows NT/2000/XP, check out TrueCrypt, BestCrypt or DriveCrypt.

For more information on PGPdisk (incl. limitations, usage problems, and incompatibilities between PGP 7.x / 8.x / 9.0 and older versions of PGP) please consult Tom McCune's PGP Questions & Answers page. You may also want to check out THIS page, which discusses PGPdisk Volume Sizes.

And Will Price of PGP Corp. responded to one user's question on the PGP Users Mailing List with the following:
 

There are several other locations from which you can download various versions of PGP (including early DOS versions). All these versions are

Plug-ins are nifty utilities that integrate PGP right into email clients and other programs, allowing you to bypass the PGPtray's "Current Window" menu option to encrypt/decrypt and sign/verify messages. PGP 6.x, 7.x, and 8.0 all ship with plug-ins for Eudora, Outlook/Exchange, Outlook Express, and Lotus Notes (though with PGP 8.0, you'll need at least the Personal or Desktop versions to get them -- PGP 8.0 Freeware does not include plug-ins.)  Moreover, you can find plug-ins from third-parties for other popular email clients.

Two plugins exist for Netscape Messenger (the email client for the older Netscape Communicator, not the newer Netscape 6.x or 7.x):

Netscape PGP Plugin
http://bear-software.freeservers.com/

PGP half-Plugin for Netscape Messenger
Click HERE

Pegasus Mail also has two plugins available:

PM-PGP
http://www.pmpgp.de/

QDPGP
http://community.wow.net/grt/qdpgp.html

If you use The Bat!, you can find a plugin here:

The Bat! PGP Plugin DLL's
http://www.ritlabs.com/the_bat/download.html

Users of MSN Messenger will find a plugin here:

PGP Plugin for MSN Messenger
http://www.commandcode.com/index_flash.html

Mozilla.org has a Mozilla/Netscape plug-in that works for the Gnu Privacy Guard (GPG) as well as PGP 6.5.8 Command Line:

Enigmail
http://enigmail.mozdev.org/

You can find links to still more PGP plugins for email clients on these very similar pages:

CryptoRights.org: Mail Clients
http://cryptorights.org/pgp-users/resources/pgp-mail-clients.html

PGP Interactions Page: Mail Clients
http://www.rmarq.pair.com/pgp/mail-clients-pgp.html

And for still more crypto-enabled IM Clients, see:

IM Crypto Tools
http://www.spywarewarrior.com/uiuc/soft18b.htm

Finally, if you're using PGP 5.5 or 6.x, you might be interested in CryptEdit+, a PGPtray replacement:

CryptEdit+
http://www.skuz.net/madhat/agent/download.html#7

You can find links to other PGP add-ons and utilities on THIS page.

PGP and crypto can seem intimidatingly complex to beginners, but there is plenty of documentation available to help you learn to use PGP. What follows are pointers to a number readily available documents, FAQ's, and help files, some of which may be sitting on your hard drive right now.

Official PGP Documentation

Almost every recent version of PGP ships with a generous collection of help files and other documentation. For example, PGP Corporate Desktop 7.1.1 includes the following files -- other recent versions of PGP (esp. those from NAI), should have a very similar selection:

You can find these documents and help files in your PGP installation directory. Depending on the components you elected to install, the PGP setup program may not have installed every one. If you're missing any of these documents, try running the setup program again. The setup program will first unpack all of its files to the TEMP directory, where you can copy the files you need. After you've copied the files you were missing, simply cancel the installation. 

The files included with PGP Corporate Desktop 7.1.1 amount to almost 10 mb of documentation (though there is some overlap among files). Those help files and other documents cover almost everything you need to know in order to start using PGP.

Other PGP Documentation

Should you find that the standard PGP documentation doesn't meet your needs, there is plenty of help on the Net available from knowledgeable PGP users. These documents and FAQ's are geared toward every level of expertise, from complete beginners to experienced veterans.

You can find still more PGP documentation and FAQ's at the International PGP Page:

http://www.pgpi.org/doc/

If you're looking for sites and pages that discuss crypto more generally, try the links on this page:

General Crypto Information

You also ought to look over the links on this page for advice on creating strong passphrases:

Passphrase/Password Info

Finally, if you're interested in getting help from newsgroups or mailing lists, peruse this page:

PGP Newsgroups & Mailing Lists

One significant , open source alternative to PGP which is based on the OpenPGP standard is the Gnu Privacy Guard (GPG):

Gnu Privacy Guard (GPG)
http://www.gnupg.org/

Although originally a *nix-based program, the GPG does have a DOS/Windows version:

http://www.gnupg.org/(en)/download/index.html
or ftp://ftp.gnupg.org/gcrypt/binary
or http://www.pgpi.org/download/gnupg/
or ftp://ftp.pgpi.org/pub/pgp/gnupg/

One interesting alternative Win32 version of GPG is the "Nullify" build of GPG, which is compiled with several modules and patches that add important functionality (such as the patented IDEA symmetric crypto algorithm, the TIGER and SHA2 hash algorithms, and RSAv3 key generation). In fact, the GPG "Nullify" page is the only source at the moment for a Win32 build of GPG 1.0.7. There is also a "Nullify" build of GPG 1.1.90 available:

GnuPG "Nullify"
http://www.nullify.org/

The last "official" Win32 release from GnuPG.org is GPG 1.2.1. You can find development releases of GPG here:

GnuPG Development Releases
ftp://ftp.gnupg.org/gcrypt/alpha/binary

GPG is itself a command line program, however, there are several Windows shells for GPG that closely mimic the core programs and functionality familiar to Windows PGP users (e.g., PGPtray, PGPkeys, et al):

GnuPG Shell Extension (GPGSX)
http://web.utanet.at/ascherst/gpgsx/

Gnu Privacy Assistant (GPA)
http://www.gnupg.org/related_software/gpa/

GPGShell
http://www.jumaros.de/rsoft/index.html
or http://www.simtel.net/product.php?url_fb_product_page=63285

WinPT
http://www.winpt.org/
or http://sourceforge.net/projects/winpt/
or http://winpt.cityofcambridge.net/

There are even several handy GPG packages that will install GPG along with WinPT:

Gnu Privacy Project
http://www.gnupp.org/download.html
or http://www.gnupp.de/download.html
or http://www.sicherheit-im-internet.de/download/gnupp-1.1-en-installer.exe (English download)

GPG Disk
http://ecstacyrain.com/qq/gpg-disk/Index.html

WinPT Installer
http://sourceforge.net/projects/winpt/

Several email plugins exist for GPG:

GPGOE (Outlook Express)
http://www.winpt.org/gpgoe.html
or http://sourceforge.net/projects/winpt/
or http://winpt.cityofcambridge.net/

GPG Outlook Plugin
http://www3.gdata.de/gpg/download.html
or http://gdataspace.de/download/gpg/GDATA_plugin_091-eng.exe (English download)

EudoraGPG
http://eudoragpg.sourceforge.net/

WinPT Eudora Plugin
http://sourceforge.net/projects/winpt/

Enigmail (Netscape/Mozilla)
http://enigmail.mozdev.org/

QDGPG (Pegasus)
http://community.wow.net/grt/qdgpg.html

You can find links to still more GPG modules and add-ons on THIS page. 

And don't worry about documentation for GPG -- there's plenty to be found on the Net:

• Beginner's Guide to GnuPG
• Building GnuPG for Win32 using MinGW
• GnuPG Documentation
• GnuPG FAQ
• GnuPG FAQs
• GnuPG Command Reference
• GnuPG Guided Tour
• GPG-PGP Basics
• GnuPG User Guides
• Installation of GnuPG - The Fast Way
• Installing the IDEA Module in GnuPG
• Installing & Using GnuPG On a Windows 9x/NT System
• An Introduction to GNU Privacy Guard (Part 1)
• An Introduction to GNU Privacy Guard (Part 2)
• Mozilla With Enigmail and GnuPG Mini Howto
• A Practical Introduction to Gnu Privacy Guard in Windows
• Replacing PGP 2.x with GnuPG.
• Steve Butler's GnuPG/WinPT Implementation Guide
• Steve Butler's GnuPG/WinPT Installation & Setup Guide
• Steve Butler's GnuPG/WinPT Personal & Corporate Email Encryption
• Steve Butler's GnuPG/WinPT Usage Guide
• Using Multiple Subkeys in GPG

If you prefer to stay away from the more recent Windows versions of PGP from NAI or if you plan to use PGP for anonymous remailing, you can use a DOS 2.6.x version of PGP, downloadable from many sources listed above. The standard PGP 2.6.2 is still available from MIT:

PGP 2.6.2
http://web.mit.edu/network/pgp.html

You might be interested in Disastry's PGP 2.6.3ia-multi, which has several significant enhancements, including a wider range of algorithms and hashes as well as support for large key sizes. See the following page for more details and download links:

PGP 2.6.3ia-multi
Click HERE

If you're not completely comfortable working exclusively at a command line, grab PGPClick, a PGPtray replacement, to use as a graphical front-end:

PGPClick
http://www.ncinter.net/~rewilson/PGPClick/

Another front-end for the older DOS versions of PGP is Envelope:

Envelope
http://web.inter.nl.net/users/E.P.van.der.Vlis/Envelope/

Still another way to use an older DOS version of PGP with a graphical Windows-based shell is Private Idaho, which you can find on the Internet in several 32-bit Windows versions. The most current, fully developed version is Alex Cameron's, which is downloadable here:

Private Idaho 5.2
http://www.itech.net.au/pi/

Older 32-bit versions of Private Idaho can be downloaded here:

http://www.ecn.org/crypto/soft/index.htm#pidaho
http://packetstormsecurity.nl/crypt/private-idaho/
http://packetstormsecurity.nl/crypt/private-idaho/

In addition to encrypting email with a DOS version of PGP, Private Idaho also serves as a front end to Mixmaster, allowing you to send anonymous email through both Type I (Cypherpunk) and Type II (Mixmaster) remailers, though QuickSilver and Jack B. Nymble are still better front-ends to Mixmaster.

There is plenty of helpful documentation for DOS-based PGP versions still to be found on the web:

• alt.security.pgp PGP FAQ (Jeff Licquia)
• Arne Helme's PGP 2.6.2 Hypertext Documentation
• The Beginner's Guide to Pretty Good Privacy
• comp.security.pgp PGP FAQ
• Getting Started With PGP
• Pretty Good PGP Reference Card 
• PGP User's Guide (Phil Zimmerman) 
     Vol. 1: Essential Topics  
     Vol. 2: Special Topics 

PGPdisk isn't the only program capable of doing on-the-fly-encryption (OTFE) of virtual drives. Several high-quality alternatives to PGPdisk exist:

BestCrypt
http://www.jetico.com/download.htm

Encryption for the Masses (E4M)
http://www.e4m.net/
or http://www.ecn.org/crypto/soft/index.htm#E4M
or http://www.samsimpson.com/scramdisk.php#dloade

ScramDisk
http://www.scramdisk.clara.net/
or http://www.ecn.org/crypto/soft/index.htm#scramdisk
or http://www.samsimpson.com/scramdisk.php

E4M and Scramdisk have been superceded by two OTFE utilities developed by the authors of those earlier programs:

DriveCrypt
http://www.drivecrypt.com/

TrueCrypt
http://truecrypt.sourceforge.net/

Those interested in any of these alternatives to PGPdisk would be well advised to check out Sarah Dean's detailed write-up of various OTFE programs: "On the Fly Encryption - A Comparison". And don't miss Sarah Dean's handy add-on utility for OTFE programs (including PGPdisk): SecureTrayUtil.

For still other disk encryption packages like PGPdisk, have a look at the utilities HERE. And for crypto apps that can encrypt individual files and folders (instead of encrypting large "virtual drives"), see THIS page.

Finally, if you're encrypting files and drives, be sure to use a disk wiping and file shredding utility. There's no sense in encrypting files if the plaintext originals can be recovered from the drive because of insecure or incomplete deletion. Eraser (by Sami Tolvanen) comes highly recommended, but there are a number of other similar programs. Once again, Sarah Dean has a helpful comparison of several secure deletion programs: "Disk & File Shredders - A Comparison".

PGP and GnuPG aren't the only OpenPGP compatible/compliant software packages available. There are a few other proprietary OpenPGP implementations that you may be interested in:

FileAssurity OpenPGP
http://www.articsoft.com/products.htm

FileAssurity OpenPGP can generate and use PGP/GPG keys. It can also encrypt, decrypt, sign, and verify messages and files that are compatible with PGP and GnuPG. For a short review of FileAssurity OpenPGP see THIS discussion.

Another OpenPGP compliant/compatible program is FileCrypt:

FileCrypt
http://www.veridis.com/openpgp/en/index.asp

FileCrypt is a command-line program.

PGPnet may not be for everyone. For more information on PGPnet (incl. limitations and reported usage problems) please consult Tom McCune's PGP Questions & Answers. If you're interested in setting up secure networking connections over the Internet, don't neglect SSH, the Secure Shell. Several high-quality SSH clients for Windows exist:

F-Secure SSH
http://www.europe.f-secure.com/products/ssh/

OpenSSH
http://www.openssh.org/

OpenSSH on Windows
http://lexa.mckenna.edu/sshwindows/

MindTerm SSH
http://www.appgate.com/mindterm/

PuTTY
http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

SecureCRT
http://www.vandyke.com/download/securecrt/index.html

SSH - the Secure Shell
http://www.ssh.com/

For still more secure networking solutions and SSH clients check HERE. And for additional information on SSH as well as other secure networking solutions, see these pages.

• SSH (Secure Shell)
   
• VPN's & IPSec
   
• PKI: SSL, S/MIME, Certificates, & Signatures

You can find still more crypto software at these locations:

Crypto Software Library
http://www.ecn.org/crypto/soft/

North American Cryptography Archives
http://cryptography.org/

Packet Storm - Cryptography Archive
http://packetstorm.decepticons.org/crypt/
or http://packetstormsecurity.nl/crypt/

pgp.rasip.fer.hr
ftp://pgp.rasip.fer.hr/pub/

Spinnaker.com
http://www.spinnaker.com/crypt/

Wiretapped
http://www.wiretapped.net/

This web site contains other pages with PGP and GPG information:

• See THIS page for a set of PGP Compatibility Tables with information on various versions of 
  PGP and what algorithms, key types, and keys sizes they support.
• For information on PGPdisk Volume Sizes, see THIS page.
• To check whether PGP Add-on Components from different versions of PGP are supported on 
  your version of Windows, see THIS page.
• If you're using the Gnu Privacy Guard (GPG) and need help with the many commands and options, 
  see this GnuPG Command Reference. And you might find this guide to Installing the IDEA Module
  in GnuPG helpful.
• You ought to consider Creating a Key Revocation Certificate in PGP.
• There's information HERE on the new SHA1 hash for secret key material used in more recent versions
  of PGP and GPG.
• If you're confused by the PGP 8.0 Freeware/Personal installation process, see THIS page.
• Finally, if you'd simply like to have a look at PGP or GPG and see what these programs look like in 
  action, check out this Guided Tour.

You can get my PGP public keys HERE.