For Ranchhand and Jimholly, they're quite correct about the Windows stuff (98 and XP)
You can, as they both said, install the older first, i.e. 98, then XP either from inside 98 or from a bootable CD.
You can also make 2 partitions, FAT32, from 98 installation, then, install 98 then XP.
Leave this now.
Now, you have 98 and XP installed, capeech?
About Linux, IT MUST BE INSTALLED FROM ITS BOOTABLE CD. ALL linux versions (or in linux language, DISTROs== DISTRIBUTIONS) are made to be bootable, so, you should have linux burnt on either a DVD or several CDs (frankly and accurately, there's a method for installing linux from hard drives from the CD-images, but i've never tried it, SO, CURRENTLY, FORGET IT).
If you begin linux installation, YOU SHOULD HAVE READ A TUTORIAL FIRST, BECAUSE IT'S NOT ST. FWD like windows. For instance, you should make two partitions for linux, one for the system itself and another smaller one for the virtual memory (in linux, the virtual memory is placed on a partition that has a size of 2X of your RAM, or slightly bigger).
So, i suggest you read a tutorial first for linux installation.
To be able to triple boot between Linux and WindowS (both 98 & XP), you'll have to install the bootloader the comes with linux (either grub or lilo => these are two bootloaders that show you a screen exactly after booting to select which OS you want to launch)...
Frankly, i haven't tried to install linux on the same HDD that has windows on it, because, if it comes to your mind to remove linux, (and it is installed on the same windows HDD, if i were you, i might have problems with booting again into either XP or 98, cause i'm not a professional

)
Ahhhh, I was going to forget. Some linux distros (versions) can see by default Windows partitions, some other, don't!
To guarantee that you can LATER make linux see them, make them FAT32 and not NTFS.
In linux, FAT32 is called, VFAT, i.e. i think they're just different names (i hope i'm not wrong as that what i've read). The default filesystem for linux is called
ext3. Windows won't be able to see linux partitions, unless you install a certain software that can view them through it and NOT IN THE WINDOWS EXPLORER !
Anyway, i think you have one of two options:
1. Either read a linux installation tutor which WILL DEFINETLY have inside it a way to install linux with Windows,,, or,
2. Install and launch this swiss-army-knife program. Although i haven't tried it, but ACRONIS is a really tough software developer:
inside this linkPardonez moi 4 the long reply