How do I tell what process owns a file?

Hi,

I'm running WinXP and trying to delete a file from my system. But
when I right click and select "Delete" I get the error message:

Cannot delete .metadata\:Access is denied
Make sure the disk is not full or write-protected and that the file is
not currently in use.

I have verified that the file is not write-protected and the disk is
not full. But I can't figure out what process is using the file in
question. Any ideas how to figure this out?

Thanks, - Dave