JR, you can't get to a DOS prompt by way of BIOS.
Are you sure you didn't disable the 3.5" floppy in BIOS? This would be under 'standard cmos setup'.
If the floppy or motherboard controller is toast, then certainly, pull the hard drive out and format it. Make it bootable though and make sure you have cd-rom drivers installed on it. After that, move it back to the orginal machine and install 98.
For some instructions and a good universal cd driver, go to
www.sigmacomputers.on.ca/dualboot.html
Essentially you will:
- create a boot disk, copy fdisk.exe and format.com to it, unzip cdsetup on it.
- boot with the floppy
- format and or fdisk depending on whether XP has already went NTFS.
- install the cd-rom drivers with cdsetup.exe
Hook the drive back up in the original machine, install windows.
BTW, my 98SE boots of CD-ROM. Is yours a backup copy or an original? I've found backup copies will still install fine, but will not boot unless created as such at the burn stage.