You need to have a Win 98 boot floppy, and boot off of that. It may be dumb, but you might wanna double check to make sure the keyboard is plugged in the right port. Don’t worry, I still do dumb stuff all the time, and I’ve been putting my rigs together for quiet awhile.
Do you have a usb keyboard ?, if so, in the bios there should be an option to enable usb keyboards in dos or something like that. Try to enable it and see what happens.