Re-set Host file to repair Internet re-direction

Your computer was infected with malware and your pretty sure you have it all cleaned off, but when you do a Google search and select one of the results you are re-directed to a different website. Perhaps you type in a website and instead of going there it takes your somewhere else. How in the world is this happening?

Excellent Microsoft article along with a fix-it tool at http://support.microsoft.com/kb/972034

updated July 2010