find the plug and or cable that says ide 1
set the hdd to master,just to be safe unplug pc from wall.
red line on cable goes toward power plug
red line on power plug goes toward cable
should use the floppy that came with 98 all works better that way.may want to lookup how to format drive
if drive is unknown you should get a wiping utility
and set all to 0's or 1's this may over write any bugs if on drive.
oh ya one more thing ,with everything unpluged find the cmos jumper and reset to default
again very important to find manual for MB.