in message
Is there anyway that I can lock a file on the desktop of a
computer that I share with others in the area.
If by "share with others" you mean that you share the same user
account, your options are limited. One option is to place the
file in a compressed (zipped) folder and password protect the
folder. Take a look at this article for more information.
How To Use Compressed (Zipped) Folders in Windows XP
http://support.microsoft.com/kb/306531
Keep in mind that if you forget the password you'll be unable
to recover your files. Make sure you use a password that you'll
find easy to remember but others won't find easy to guess.
If your computer has XP Professional or Media Edition installed
and each user has their own account, you can use NTFS
permissions to restrict access. If that's the case, look at
these articles.
How to set, view, change, or remove file and folder permissions
in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;308418
How to create and configure user accounts in Windows XP
http://support.microsoft.com/kb/279783/
Good luck
Nepatsfan