Hi wrag, if its the windows cd then its pretty easy to check, compare the archive files with a diffrent windows cd which has the same version of windows. If you say its not on your sons cd try to extrakt the file from that cd and put it in place of yours, keeping a backup of yours.
Also might use a file compare tool to compair the files.
Is it only on the one computer?
Then it might be a diffrent issue, can be faulty motherboard, bugged bios version, to aggressive settings for the graphics card slot.
Since you had the same bug on two diffrent cards i would suspect that its not the card.