New monitor broke my display driver?

[beserker15]

Well, here's the story, I just hooked up a new widescreen monitor and reinstalled my display drivers. Now that it's installed, none of my games will run. When I try to load up ati tools, it says "the kernel mode driver does not seem to be running." I'm not sure what that means but now nothing can really run and all I can do is surf the net. I need help!