Here is how i would proceed.
Keep in mind this is AFTER you have located all the drivers you will need and have backed upeverything important on that drive...
Travel to bootdisk and DLoad a Win98SE bootdisk.
Extract it to a clean floppy.
Boot with the floppy in and choose "Start with CDRom support" (#2 i believe)
At the A: prompt type format C: /s /u and hit Enter. This will erase all your data are you sure? ? choose Y and hit enter.
Re-boot the same way. Watch the boot screen it will tell you which drive is your CDRom. Put the Win98 CD in and again at the A: prompt type in your CDRom drive letter (E: or whatever) and hit Enter.
At the E: prompt type setup and hit Enter...
Grab a beer, this will take awhile.
Enjoy !
patio.