[Warning]I will not and can not take responsiblity if something goes wrong. I haven't tried this myself, but in theory this must work.[/Warning]
Do you want to (1) keep the XP Pro installations on both drives, or (2) do you want to replace one of the installations with win 2K?
For the first option:
Just do a normal win 2k install as usual, at some point I believe win 2k setup asks you to remove the XP Pro installation or if you want to keep it. If that isn't the case (the asking bit), then first install Win 2K and then install XP Pro. Xp Pro asks you wether or not you want to keep the Win 2K installation and it automatically creates a boot menu for the two installations (Win 2K and XP Pro). To add the XP Pro installation on the second (or first if you like) hard drive to the boot menu, you have to get a program called BootPart (Which I included here). With this program you can add installation of every windows to the boot menu used by systems based on the NT technology (Win 2K and XP Pro (and Home) are based on that operating system) and even Linux. Make sure you read the instructions very carefully though, you can mess up the boot menu and never be able to log on to a installation again!
remove the XP Pro installation on the second hard drive (or first, if you like), by doing a format. Yes you have to remove the complete installation, you can't just overwrite the 'new' (XP Pro) files with the 'old' (Win 2K) files. I you have already split up the drive in two or more partitions, move all the files you want to keep to the partition where XP isn't installed, or if you haven't partitioned, just backup the files you want to keep to a floppy or CD/DVD. After removing the XP Pro installation, install Win 2K on the disk and after completing the installation, if it hasn't asked for adding the XP Pro installation to the boot menu, use the program supplied with this post to add the installation to the XP Pro boot menu.
If you have worked with computers long enough, you will find out that theory and practice are two completely different things in computerland. If you have any doubts in doing this, then don't do this, or ask someone with more experience in this for help. I have answered your question, because we are all friends on this forum, trying to help eachother out, for as far as we can. [/Warning Conclusion]
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS