Hello, i have a Dell Dimension E520. About a year ago, I purchased an upgrade video card. I bought a GEForce 8500 GT 512 MB PCI Express x16. After installing this, i started to experience some major problems that i have never encountered before. I don't know too much about computers but have been trying to learn more and more. The problems that have been happening are since the video card installment, i have been experiencing freezing of my PC. There are times when i leave my PC on and come back after a few hours only to find that either my PC has frozen, or the blue screen of death has appeared, or my entire display is totally messed up with all sorts of weird colors all over the screen. There are times that i am online in a MMORPG game that i play when it suddenly freezes on me and self-reboots. I'm not sure if this is because of the video card or a virus. I consistently run Norton every week and most of the time, it picks up nothing. I have no idea how to solve this problem or what the cause may be. Please anyone help !!!!! Thank you for your time and i hope to hear from anyone soon.