Appcompat.txt is not the problem. It contains information about the problem. Open it up in notepad, and you'll see what I mean. When you get an error message that references appcompat.txt, it'll usually give you the full path to the file. So click on Start, Run and enter:

notepad C:\DOCUME~1\username\LOCALS~1\Temp\WER7b4e.dir00\a ppcompat.txt

Where "C:\DOCUME~1\username\LOCALS~1\Temp\WER7b4e.dir00\ appcompat.txt" is replaced with the actual information that was presented in the error message. You'll see a lot of technical information…