pc shut down after installing antivirus & continues reboot

my computer is continues reboot and reboot after installing an anti virus how can i repair it... my suspect is the OS was damage by the virus...

Boot to safe mode, F8 & uninstall all AV garbage.

was it AVG 2011?

Sounds like Windows Antivirus 200x. Get SUPER Anti-spyware and HijackThis. Check places like BleepingComputer to get full details on how to remove it.

Not AVG its just AVIRA..

honestly i would boot into live linux DVD so windows is not loaded and can not do anymore damage but this is just my recovery method, backup only your important files like documents and pictures leave programs and other stuff that can be downloaded again. Format reinstall clean and first thing before anything goes back on that computer is spybot search and destroy and upload and immunize it then antivirus and check firewalls and open ports on the router.

Once security is back up move your stuff back and start setting up.

I use a decent product - Hiren's BootCD. It has both a Linux and WinPE live cd.

Although I wonder if they make a Windows 7 based PE boot cd.

why would you want to do that, linux boot cd's are better due to the face that windows can not understand them so it will bypass any security windows has, you don't want the security open again while your trying to do a recovery.

It is possible to get a windows OS to boot from USB but cd i am not sure of but you can have backup usb windows if your interested.

I use them for Antivirus & Antimalware and a good offline defrag when working on clients' computers.

Last I checked, MalwareBytes' didn't work on *nix and I am not particularly fond of ClamAV.

A good, speedy, 16GB USB drive with a Win 7 PE and the applications I need would be nice.