How do I restore windows 7 to manufacturer setting

Well about a week ago I got a virus now its at the piont where I cant access the internet because the virus has taen over everything. I did a system restore which made it fine but than I got the virus again. When I did it a second tine it got saved before I restored so I'm at the point where I can't do anything. Any suggestion? I lost all my cds when I moved so what are the options now. I still have the cd key but that's it. Help pleasee

We can't tell you how to restore to factory condition if you don't even mention what make or model computer you have.

If it's a computer which came preinstalled with Win7 then it should have a partition which can be run from boot by tapping a hotkey to recover to factory condition.

If not or if that partition has been damaged or overwritten, then you'lll need to find a WIn7 retail installer to clean reinstall with the Product Key on COA sticker or your retail packaging.

Here are steps to unlock any retail installer to choose your licensed version and get a perfect reinstall: Reinstalling Windows 7