Just a tip. I running xp home on Gigabyte ZXR m/b, Athlon 1.4ghz., 512 mb ram, asus dvd, liteon burner, promise ata100/raid. After updating system with critical updates, the controller for dvd and burner became inoperable. After removing critical update Q810833, burner and dvd able to read and run whatever I threw at them. Hope this helps someone else who suddenly loses dvd, cdrom or burner after installing this hotfix!