You can only encrypt files, folders and sub-folders in XP Prfessional, based on the Encrypted File System, namely EFS. In addition, the HD has to be NTFS. This facility is not available in XP Home.
thanks for the reply. Well I am running xp home and my hard-drive is in the NTFS format. I have found a way to password protect a file but only in a zipped folder, By right clicking within the zipped folder and selecting "add password" thanks for the help