I have been doing this for quite a while. Firstly you will need to partition the drive in two, the 2k partition should really be bigger than the win9x one. Install win9x as you normally would, then run 2k setup. remember to choose the option to install a new copy of 2k. windows 2000 will sort out the boot loader for you by altering the MBR on drive C:, giving you the option to start "microsoft windows" or "microsoft windows 2000"