My wife's mother board failed.
I took both her hard drives out and
installed them in another computer I had.

It starts to boot gets well past the bios but it hangs up
were it says on the screen "Starting Windows" above a wide
white line.

Does Windows 2000 only work on the mother board it
was installed on?

WIN2K doesn't key to the motherboard. That started with Xtra
Proprietary. You probably have problems with the device drivers the MB
requires. Did you try to boot in safe mode ? Hit F-5 at start-up and
boot in safe mode. Then you should be able to install the drivers for
your MB. It should have come with a CD with them... You can also hit the
ESC key at boot-up to maybe see what is actually hanging...
-dave

Thanks Dave
No did not try safe mode.
Plan B.