how do i find out what program is using a file?

[DJFuji]

I'm trying to delete a directory in windows explorer, but each time i try, windows tells me that another process is using the file or folder. How can i tell what process is using it? I've already tried going to virtual dos mode to do it, but it won't let me there, either. It'll probably work after i reboot, but i'm wondering if there's an app out there that will detect what process is using this file...

(WinXP SP1)

 

[MrChad]

Process Explorer should do the trick.