Multi boot

Yes. This is best order, and Partition format.
First Win98 on a 2G FAT (not FAT32 or NT4 wouldn't boot)
Second Windows NT on FAT if you want Win98 to access the partition, or NTFS if you dont care. FAT will limit you to 2G, NTFS you can create upto 4G during install. If you go with NTFS you will want to apply SP6a before installing Win2K. Win2K using a newer NTFS that could render your NT installation unaccessable unless you SP it first.
Third Win2K again FAT if you want it visable from both Win98 and NT4. FAT32 if you want it visable from only Win98, or NTFS if you want visable from only WinNT.
*At Systinternals.com they have a driver that allows Win9x to read (free) or read/write(small charge) NTFS partitions, and FAT32 driver that allows WinNT to read (free) or read/write(small charge) FAT32. BUT you still need that "System" Partition FAT, so that NT can boot.

easy steps fdisk the hard drive create a primary DOS partition for 98 create a second
primary partiton for nt and do nothing with the rest for win2k.
install 98. then put in the nt cd boot from that and install that on d: when you boot again you will have a boot up screen to choose which os you want. when you want to install win2k server just boot from it's cd
and install it in the blank part of your hard drive and it will add its name to yuor boot up choices.
I run all 3 myself and never have a problem I have redone them many times.
it's real easy you'll see