I'm not a tech genius at all. Just a regular guy that has gotten mad at his own comp several times. That .dll file issue sound like it may be a graphics driver update is needed through Control Panel? But then again I don't know how often you play stuff, or how much tech stuff you know personally, so that may be useless info. (Yet if not, I suggest doing a web search for that file and see what it is.) Although I doubt you'll wait more than a day or so for a direct answer here as to what it might be.
Also I wanted to say: Windows 7!? (jokingly of course)
You haven't updated to Windows 8!? You are totally missing out on how much you can hate the new OS! It's great! You need an basically an extra OS desktop-mod (
Start Menu 8) just to get your Menu Button back! It's great! And then you can cuss yourself out for not just waiting a little longer and getting windows 9 or 10 or X or whatever the quick switch was once everyone hated Windows 8!
Seriously though, I'm sure you'll get your problem sorted soon, and you'll be out dying repeatedly with the rest of us!