Download the program (here)
Open a command prompt by going to Start, Run, and then typing in cmd and pressing Enter. Leave the command prompt open, and close all other open programs. Press Ctrl-Alt-Del and go to the Processes tab. End the process Explorer.exe and leave the Task Manager open. Go to the Command Prompt and find the directory where the undeletable file is. Type DEL <filename> to delete the file. Go back to Task Manager, click File, New Task, and type in explorer.exe and press enter. Close Task Manager and the command prompt.
Open notepad and click Save As. Find the undeletable file by ‘All Files’ from the file type box. Put “a” in the front and back of the file’s name, save the file and overwrite the existing file, then delete the file normally.