a disc read error has occurred,this message has appeared in the top left hand corner of the screen that has also gone completely black,it tells me to press control+alt+delete to restart . after doing this nothing happens it just reverts to the mesage again.This happened as I was trying to clear the screen of at least 2 other sites (security ones plus my own AVG system) appearing at the same time.Bearing in mind that I am 74 and a complete novice can anyone point me in the right direction.
cheers, Glenngary

P.S. I am using a lap top to post this message.

Assuming you have your Windows 2000 CD you can boot it into the Recovery Console as seen here:

http://support.microsoft.com/kb/229716

Try the command FIXMBR

Your error indicates a damaged Master Boot Record or else it indicates a failing hard drive.