You need to install Win2K first to make it dual-boot with WinXP. You should also create 2 different partitions for the two OS's. Since you have WinXP already installed, use FDISK to delete the existing partition (I suppose you have only one now), create 2 new partitions, make first one active, install Win2K on it, and then later if you install WinXP in the second partition, it will be easy. XP will take care of dual-boot automatically, provided Win2K is installed first. Otherwise, you have to use some software like Partition Magic or System Commander etc. to make your job easy. But if you want Win2K Server, you need to get either V-Comm's "System Commander" or Paragon's "Hard Disk Manager". If it is Win2K Pro, anything will do. This is not going to easy, but a little tricky unless you do everything correctly. Otherwise you are going to be spending a lot of hours. Read the documentation first before you attempt to do anything.