Windows 7: Reinstalling Windows 7

Not sure if this is the right forum but here goes.

My computer has a ton of viruses and I want to do a clean reinstall of windows 7. My computer originally came with Vista but a year later I upgraded to 7 Home Premium. I upgraded by buying a product key (no disc) from the Microsoft website and downloading some file/application to install 7. I cannot find this file nor can I find anywhere on the Microsoft website which would allow me to download it again. Any help?

Yep.

You can borrow a disc from a friend and use your key.

Or you can use your Google-fu to find the ISO online and burn that ISO to a disc.

Hint: My Digital Life

Hint: askVG.com

Steps to get a perfect clean reinstall of factory OEM: Reinstalling Windows 7

update:

i downloaded a 7 .iso file and burned that to dvd
in the computer bios I chose the dvd drive as the primary boot
here's the problem
when I hit f12 and enter the boot menu, then hit boot from dvd drive it just boots to windows as usual and not to the windows install menu as i want it to. any idea what the problem is? (the dvd is in the drive)

Did you slow burn the DVD using ImgBurn at 4x speed? If so confirm the ISO or download another and try again, or write ISO to flash stick as given in the steps I linked just above.

If it won't boot from the DVD, my first guess would be a bad download or a bad burn.

Download again or check the hash on the one you already have.

Or use another burning app, such as ImgBurn.

Burn at a relatively low speed, 4x to 12x.

Use high quality discs--like Taiyo Yuden.

i burned it using ultraiso at 8x. also when the burning was done, it said verification failed. could this be the problem?

Most likely.

Try another burn or download. Preferably using ImgBurn. It's certainly possibly you could have a bad download, in which case a jillion burns won't help.

Did you read the steps I gave in Reinstalling Windows 7 to get a perfect reinstall?

Sounds like you ignored the very first step which is not a good start.