Win Xp with Win 2000

Install the operating system in a different directory

Once you have the drive partition ,run setup to install W2K with a clean install

Windows XP should be the last OS installed

You can, but you may run into problems... what to do

Install Win2k in z:\winnt (where z is the drive letter) as a clean install.

Install WinXP in z:\winxp

Make sure your ARC pathnames are right, then you are raring to go. Now you may run into problems, because they share a common root (ie. Program Files, Documents and Settings)

It is not recommended to install both operating systems on the Same partition, however you can certainly install them on separate partitions,

If your whole hard drive is 1 partition with 98 on it and you don't want to reformat and repartition because you fear loss of info., then you can use a program such a Partion Majic to resize your hard drive into 3 separate partions without losing data.
Then you can safely load XP onto 1 partion, 2000 onto another and keep your 98 on the original partition.