key code for office 2000

1)the original package showing cert of authencity does not provide a25 character number to enter. What code should be used?
2) after running norton clean sweep it deleted register files and other files. Now it gives an error 30 (this is for millineum software). If the restore disk is ran, it will wipe out ofther programs added. There was no backup made and it came installed on the computer.