Give Unlocker a go:
http://ccollomb.free.fr/unlocker/
It will unlock any process that might be accessing or stopping you from deleting the file.Quote:
It has many other flavors:
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