http://support.microsoft.com/default...5266#appliesto

You might have bad RAM or areas on the HD then. To check the HD, you can try running "Chkdsk /f /r" from the command prompt - it may ask to restart your computer to do this. For testing the RAM, you can download Memtest86 - unzip the ISO file inside, burn the image to a CD, then reboot the PC with the CD in the drive so it boots from it