Need Help Deleting File

[Tuds75]

I downloaded a movie (Batman Begins, good movie) from a file sharing program. When I open the file it doesn't play. It just locks up Windows media player. After I closed WMP I tried to delete the file, but I was promoted that the file is "in use by someother program or person. Unable to delete". I restarted my comp and tried to delete file. Still got the same message.

I just want to delete this file because it seems like my computer is not runnign the same since tryin to open this file.

Please tell me what I can do to remove this file from my computer. Any help is greatly appreciated.