IE & MSN becomes useless

I deleted a few things that were highly suspicious of being spyware, according to my anti-spyware programs. Afterwards, Internet explorer stopped working, and so did MSN. I tried to install IE6, it said that I have a newer edition and refused. I tried to install IE7, but couldn't pass the "genuine check"--I don't know why because my computer is 100% genuine. Now I have to use firefox, which is what I prefer, but the problem is that sometimes I have to use IE and now I can't. Please help.