As previously mentioned on my blog, I use a tool called 'Unlocker' which unlocks used files when I can't delete them.  Here is the list of changes:

Unlocker 1.8.6 - 29/02/2007

- Fixed bug: Delete, move and rename should work better now.
- Fixed bug: Non DLL handles are now listed properly on Vista.
- Fixed bug: List files are compatible with Total Commander again. This bug appeared in version 1.7.7. Thanks to Icfu for spotting it.
- Improved behavior: The executable includes a manifest for better Vista compatibility.
- Promotional feature: Added fully optional shortcuts to eBay during the installation. Simply untick "eBay shortcuts" in the choose components page during install if you do not wish to have those.