you might want to do a format if you do not have a lot of expertise with regedit. It can be hard to get rid of a rouge program that is trying to take over your computer.
I have no idea what kind of site you were visiting, but some sites are very dangerous. They can steal your computer to do all kinds of things. Free software and porn sites can do that. You get your phone bill and it's for thousands of dollars for 900 number phone calls to Russia!
This could just be a botched install/uninstall.
You could try running msconfig and see what progams are being loaded. Post some screen shots perhaps of what is running, maybe with more info we can help you find out what is going on.