Considering I've yet to come across a single legal game download site that uses torrents OR disk image files like MDF, I'll go out on a limb and assume we're talking about a pirated game. Something it's against the rules of this forum to discuss.
So, I expect a moderator will be around shortly to lock this thread. In the event you downloaded something in a perfectly legitimate way, just send a report to a moderator demonstrating as much and they'll unlock the thread. Otherwise, you should know that, generally speaking, the price of a free (i.e. pirated) game is you get to provide your own support if something doesn't work right.
I downloaded a game via torrent which included .mdf files that I was able to mount. Though, after I uninstalled the game it wouldnt allow me to delete the .mdf file itself. Ive tried unmounting it, uninstalling the virtual drive. It says the file is being used in the system. Help!