win98se/older pc/boot problem

PC: an older gateway 486dx/66mhz, 32meg ram, 1.2gig hd, pci/isa motherboard, phoenix bios 4.04, intel p’n’p extensions, 10/100 ethernet card.

problem: installed win98se from cd. everything was great till the network settings and properties wereentered. upon reboot, there is no video (won’t even take monitor out of standby), the floppy drive runs incessantly, post codes beep–one long, two short; then repeated sounding of three short. won’t boot at all from hd or floppy.

I’m stumped.any ideas???