My computer will not load windows because the system file is missing or corrupt!?

how do i fix it? i do not have any disks to repair it.

My computer will not load windows because the system file is missing or corrupt!?virus

You will need the disc to reinstall windows.

If you contact your manufacturer they will supply you with the disc for little or no cost

My computer will not load windows because the system file is missing or corrupt!?anti virus

Weeelll... it's all over for you. Get a copy of Windows somewhere cause you're gonna have to reinstall Windows
Without any Recovery Sytems Disks there's nothing much you can do but have it serviced.
You pretty much need to frag the system file, which pretty initiates a fresh installation. Long story short, unless you're savvy, and/or have a lot of time on your hands, you should start over with a fresh installation. My advice:

Go to www.newegg.com and purchase a new internal hard drive. This will qualify you to get an OEM copy of Windows. I still prefer Windows XP Pro, but go ahead and try Vista if you like. Also, please consider Ubuntu. Install the new operating system on the new hard drive, probably labeled D: . In all likelihood, the files on your old installation are intact on your original hard drive. You'll need to reinstall software, but you shouldn't lose any data.
boot the system and press F8 while booting. An options screen will come up. Choose Use Last Known Good Configuration. Hopefully that will work
if your computer doesnt prompt before windows loads for an automated system recovery then you cant really do anything unless you have windows disks.
sounds like a virus got you. not much you can do except get a copy of windows and start fresh.