You will get the following error messages when you try to delete a file/folder which is being blocked by the System or Application Processes running in the Task manager:
Access Is Denied
Sharing Violation Error
File/Folder is being used by applications. Please close the application and then try again.
You need to kill the handle. To kill the handle, use Process Explorer from Sysinternals (at URL: http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx)
How to delete the handle:
Run Process Explorer
Go to Find menu > Enter File/Folder name and then click on Search. You will see a list of processes blocking the file/folder.
Right click on the process and then click on Close Handle > Click Ok for confirmation.
Now you can successfully delete the file.