Is there is any free software to recover password for Outlook Personal Folder(pst)?

Answer 1

Nothing free sadly but the Passware Office recovery program works well though (My friend found the full version free on bearshare, if i remember it's a few megabytes to download ;).

http://www.lostpassword.com/

Try the outlook one for free maybe the first two letters it finds will jog your memory
http://www.lostpassword.com/outlook.htm