Back your machine up about two weeks.
Go here to get tools and instructions on how to fix: http://www.bleepingcomputer.com/virus-removal/remove-win-7-internet-security-2011
Once this is run you may still have problems. In two computers (both laptops), every folder and file was marked hidden, so I had to unhide all files and folders. Then all shortcuts had been removed from the start menu. I had to rebuild, luckily I have other laptops with same menu so it was just a matter of copy and paste.
It is fixable.