I used to have problems with deleting or sometimes just renaming files because windows said the file was "in use". One day I just Googled the problem and something called "Unlocker 1.8.7" came up. If you have trouble doing anything to a file Unlocker will show you all the processes using the file and gives you the option to kill the process so you can continue working. If you want it the link is here.
http://ccollomb.free.fr/unlocker/ (http://ccollomb.free.fr/unlocker/)
Its just like taskmanger, Only way better organize for people who are not to familer in ending a process from the taskmanger.