I lost windows 2000 before when I had triple boot laptop. In order
to get the windows 2000 back, you would need the boot.ini
file that is included when you have two types of windows operating
systems installed. Then, I ran the windows 2000 and booted off
the CD-ROM. I choose the repair option for an exsisting OS,
and got it fixed that way. After repairing the windows 2000, it
then ran the linux rescue boot and installed the the boot loader.
Hope this helps.
Details about triple boot