Comment on PGP Desktop Professional

I see no reason to use this software. You can use GPG; It is free and Open Source (anyone can check if there's any backdoor hidden). And it is updated more often.
Use TrueCrypt to encrypt your HD (a chosen volume). It is FREE too.
For single files, just compress them (zip or rar). I use BetterZip (AES 256bit). You can share that file(s) without worrying about compatibility on the other side.