I'm saying the following assuming you're not gonna split/partition your HD into sections, and use it as a whole instead.
Windows 98: I think that if you boot into a command prompt, you can type FDISK and be able to partition it. Just answer "yes" about the FAT32 question, and choose "Create primary partition". Answer "Yes" when it asks if you'd just like to use all the space possible. After this is done, and you shutdown and reboot, then use the CD to install Windows 98. (I think this is possible. If not, you can make a boot disk using this article:
http://content.techweb.com/winmag/columns/explorer/1999/1025.htm
Windows 2000/XP: When you boot with the CD, just go through with the install. When it gets to the part about partitions, it'll ask you to choose the partition to install in. Choose the one that should be visible, and format it with NTFS (unless you're gonna dual-boot, which I won't go into). Then, continue as usual.
BTW, just out of curiosity, what's your computer consist of?
