Keyboard and Mouse Problem

I have a gateway system I’m trying to troubleshoot. The keyboard and mouse stops working in windows 98. They work when booted from a dos floppy or when I access the BIOS during boot up. After Win98 starts to load the num lock, cap lock, and scroll lock lights start blinking. Any suggestion on whats causing the problem. I have tried a fresh win98 install on a spare HD to elimanate win 98 as the source of the problem but that was unsuccessful also.