It sounds like it may have modified some video settings. Check that first.
Then get these programs to help clean out the leftovers the program left behind.
Crap cleaner> (I didn't name it) www.ccleaner.com
Turn on all the features and run it. You're going to be amazed at what it finds that you didn't know was there.
Find Junk Files> A neat little program. I'm sorry but you're gonna have to Google for it. I can't recall where I got it. Might have been Major Geeks, not sure.
AdAware se and Spybot S&D, blah blah.
It might have left behind some ad/spy ware you need to get rid of also.
Hope this helps...