Windows 2000 install gone bad

I wanted to help a friend by installing W2K on his IBM Netvista desktop. I let the PC boot up from the hard disk, gave it an administrator password and then the PC rebooted itself. After it restarted it asked for the Adminstrator password, but it would not accept the one I had entered. I tried Caps Lock and various common misspellings of the word but no luck.

The PC came with no installation media. It was all on the hard disk. Lucky for me there is the MS ID codes for the software pasted on the outside of the PC and we have all the receipts from the purchase.

How do I get a legal copy of the installation disks? Do I need to reformat and reinstall everything to correct the problem? Are there any other options available to fix the problem?

Thanks from
Mr. No-good-deed-goes-unpunished.