Consider this:
When asked to reboot, eject the CD and remove it. Enter the BIOS before the reboot and verify the HD is only device to boot from. Disable all other HDs. Exit & Save settings. Reboot.
You'll either boot off the partial W2K install or the machine will hang-up or error indicating that something's wrong with the BIOS settings, the drive, the partition, or the install. Either way, you'll know.
As per someone else's comment, run FDISK or PartitionMagic or something and verify that the partition is properly set and active. Then again, W2K shouldn't install without straightening that out for you.