Unlocker is a very useful Explorer extension that allows you to unlock those files and folders that cannot be deleted. Just right-click on the file and select "Unlock". Usually when trying to alter or delete a file/folder that cannot be changed you will receive one of these error messages:

• 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.

With Unlocker you can simply "Unlock" it.