My video card isn't working well?

Usually I play games (new games) at medium-high quality. Now, my games get slow even on the lowest quality!!! I have NVIDIA GeForce 8500 GT. All of this happened after I got a virus. I sent my computer for repair, and it came back like this. I have no current viruses on my computer. I tried to reinstall the games and install a new driver, still nothing.|||Viruses can be tricky and real dangerous to the operating system. It doesnt sound like you have a video card problem. But usually when you get a virus, even after a virus is gone...there can be traces or even hidden services that the technician easily missed. All these traces/services will put a halt on your memory. Sounds like your original Video card is ok, You should do a System restore to the earliest timepoint there is, if that doesnt do it you need to backup your files and reinstall windows. Be sure to download a Good anti virus program (AVG is a good one and its free) and stay up to date on your updates.||| They may have ruined something or knocked around something important and busted the connection port or any thing really, Even the best make mistakes. Or maybe try this, ok Disk clean up, when that's done De-fragment tool then Check Disk tool as well, the Check Disk tool only works on restart or boot up, this may help.