After starting up my computer the screen display sometimes suddenly disappears behind a series of multi-coloured lines which can best be described as like a barcode covering the whole of the screen. When this happens I have to shutdown by powering off and when I reboot the machine either i) it won't reboot or ii) it does but the problem re-occurs. This can happen several times in one night and then not happen for several days.
In comparison to the evolution of the earth, my computer skills are in the ice-age... so if you can help, please keep it simple...verrrry simple!!
Thanks
Brendan

found on the web:
http://en.allexperts.com/q/Video-Card-Prob...d-problem-5.htm

When I was playing WOW the other day my screen looked a giant multicolored barcode. I could still see my mouse pointer moveing around so i left the game. In the desktop the barcode look was still there so i rebooted and it cleared up. But now it happens at any given time in game or just when the computer is sitting on. I took a screenshot to see if it was in the moniter or not and the screenshot looked like a barcode.



There are two possibilities....bad connection or the video card is dying :-(

Turn off the computer, open the case and remove the video card, and system RAM memory sticks, use a pencil eraser to rub the contacts on these items clean and then use an alcohol pad to clean and dry well with a lint free cloth.
Reinstall in the computer and hopefully it solved the problem.

If the problem is still there , then the 2D processor on the video card is going bad....nothing to do but get a new card. Hopefully it might be under warranty.

Thanks very much for the reply and the advice - will give your suggestion a try (or more accurately ask someone who actually might know what they're doing..). The computer is out of waranty, so fingers crossed!!
Thanks again,
Brendan