For getting rid of stubborn files on a PC, such as when you get an error message like "This file is in use. Close the program that's using it." or some such silly nonsense ...
First, try booting in Windows Safe Mode. In XP, I think you do that by hitting F8 when you are rebooting. If that doesn't work, there's a free program called
Unlocker that nicely integrates with Windows Explorer to provide right-click functionality.
If you use Windows Media Player's "Monitor Folder" feature, that can lock a folder that contains files you want to delete. Turn that feature off, close Media Player and try again.
There's a few things to try...
BigJohn