starman. I'm 99% sure that your motherboard is fine, as is BIOS, so you relax about that. You may want to consider purchasing a CD-ROM drive for your laptop in case a reinstall is necessary, or if you insist on getting W2K installed on the laptop.
With the drive installed in the desktop PC, the W2K install loaded drivers specific for that PC's motherboard chipset, and all of its peripherals, such as a NIC, sound card, etc. Taking that out and placing it in the laptop probably won't work, even if you get it to boot. The hardware just won't match, and likely results will be blue screens and reboots.
What drive letter was assigned to the laptop hard drive when it was in the desktop? And, did you do an upgrade of 98 to W2K or a format and install of W2K?