The freeware Tizer UnLocker helps to remove, rename, or move files or folders that are temporarily locked by other processes.
You can browse for files and folder or just right click locked file or folder for removing lock.
In some cases, files cannot be accessed due to Windows file-access bugs or viruses but this is the solution for those files.
The software will list all locked running processes on the computer system and use a variety of methods to allow you to access these hidden files, including attempting to unlock the handles, kill the process holding the file open, and allow you to rename, move, or delete them.
The program (download it here) works on Windows XP, Vista and 7 and is free and for personal use.