<< if done correctly, you should be able to install win2k after winxp just fine. are you sure you installed xp and 2k on different partitions? >>
100% sure.. WinXP is on C: and Win2k is on D: maybe its something with my boot.ini, here is what it looks like...
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINNT
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Microsoft Windows 2000 Professional" /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /KERNEL=kernel1.exe