I would first start to find out how Windows saves this data internally. Hopefully, this is accessible via the registry. Then, use the appropriate Win32 Registry module to edit that registry.

Of course, you still have issues to deal with, such as how you decide to run the script on 3000 PC's...but that's easy enough with a login batch script (or equivalent) and running Perl over the network. UPDATE: Yep, the above post is right. Desktop.ini. I should have known that! I congratulate Microsponge for not using the registry in one place. The days of ini files were so much more fun (and reasonable).