Unlock files in Windows that is used by other processes

If you can't delete a file if some program is locking it, but you don't know which or do you get a message like this:

• Cannot delete folder: It is being used by another person or program
• Cannot delete file: Access is denied
• There has been a sharing violation.
• The source or destination file may be in use.
• The file is in use by another program or user.
• Make sure the disk is not full or write-protected and that the file is not currently in use.

, then these applications can help you.

I use both and they they do the job well.
Both runs on both 32 and 64 bits Windows.

LockHunter:
http://lockhunter.com/

Unlocker:
http://www.filehippo.com/download_unlocker/