i've had this before, after installing avantbrowser and uninstalling it...try this link...i had to reregister several DLLs but it got it going again...
http://www.tek-tips.com/gviewthread....608/qid/764180
don't quote me because i dont know what platform you are running, but here are some other links that will help...
http://support.microsoft.com/default...;EN-US;Q281679
http://www.searchthingy.com/problems.htm
let us know how you made out...