The Geek Squad wants to replace my hard drive and reload Windows because they say it is infected with a virus and my warrenty won't cover that.

Your warranty would not cover fixing your computer.
Depending how badly the virus infection is, the virus or viruses may be with a virus program without re-installing Windows.
If Windows needs to be re-installed then in most cases the hard disk will not have to be replaced, it only need the the hard disk wiped clean and then re-install Windows.

That is just moronic - you have to replace the hard disk only if it has physical damage,. To remove a virus infection all you have to do is to reinstall Windows and perform a full format in the process.
Never call them again, they are trying to stiff you.

You don't have to replace the hard drive if it still works. You can reformat it by doing a clean install of windows. It's relatively easy. Just go to your cmos, tell your computer to boot from cd, put your windows cd in your drive. Boot to the windows install cd and follow the instructions and answer the questions on the screen. Good luck and let me know if you need anything else.