you need to install 98/ME first, then 2000. when prompted to upgrade choose no, then do a clean install on a DIFFERENT parition then 98/ME. Here is the guide from this site.http://www.duxcw.com/digest/Howto/software/windows/dual/index.html
Pentium 3 1000 @ 1100 ( windows 2000 server), Abit bx-133, 256 Mb Mushkin Rev.3 cas 2-2-2, ATI Radeon
AMD Thunderbird 1.4 @ 1.63 (24/7) IWILL KK266R , Corsairs pc 150 cl2, Leadtek GeForce 3 