Dual Boot WinXP and Win98

Hey.

My grandfather needs to dual boot Windows XP and Windows 98. I recently did a rebuild for him so he could have some decent hardware that will keep him going for a long time. He had 98, we got XP. Problem is, his Weatherstation equipment is not compatible with XP, apparently. He has been back and forth with the tech's, and there was nothing (something about: the company who sells the product supports it, but RadioShack also buys direct from the manufacturer, but offers no support. Since he bought it from RadioShack, the support and updates from the other company don't quite work.. or something)

Anyways, how can you dual boot the two systems? Worst comes to worst, I could always just load up Knoppix, make a small partition, and install Grub.. but I assume windows has a built in way... ?

Partition the disk first, then install win 98 then install XP.

http://www.microsoft.com/windowsxp/using/setup/learnmore/multiboot.mspx

If you need to install Win98 after an XP install (even though it's not the preferred method), you'll need to follow the directions at Doug Knox's site here...

How do I install Windows® 98/Me after I've installed XP?
http://www.dougknox.com/xp/tips/xp_repair_9x.htm

... the only way you can use the above procedure is if C: was formatted using either the FAT16 or FAT32 filesystem, but it is an option nonetheless. The preferred method of dual booting the two OS's would be to follow Kendan's suggestion.