Question Retro PC problem

[Asdfggg]

Yes, I know, it's about an old PC, but I just wanted to use it for nostalgic purposes. But the problem I have with the PC is that when I turn it on, it won't boot into the CD automatically, I have tried using Windows XP professional and windows 98 SE, but when I turn on the PC it just stays stuck at the gateway logo. I have tried all the keys on the keyboard and a combination of some, and when I press f10 or DEL then it says "Preparing to run system setup..." And gets stick, I have waited for 15 minutes and nothing happens, maybe I need to wait even longer, but I don't think so, but I have seen many other retro PC's that instantly went into the CD boot menu. Also my floppy doesn't work so that is most likely why windows 98 won't boot, but why can't Windows XP? I had another motherboard and the floppy worked, but the motherboard didn't display anyway, so there is a problem with the floppy slot on the motherboard, but I am just getting an external floppy drive anyway. So could it be the motherboard is broken, or do I need to do a certain key combination to get into the boot menu? Or could it be something else like the CPU or the RAM? If you know well about retro computers, please help.
System:
MOBO: Gateway 4000676 a-19243-403
CPU: Pentium III 866 MHZ
RAM: 128MB pc100

 

[tennis2]

Reset the CMOS on the board. This will be a small 2 pin jumper on the board which you short the pins for a few seconds (10 seconds is usually fine IIRC)

Enter the BIOS setup, locate the "boot device priority", and set the optical drive before the hdd.

 

[Asdfggg]

I have put the CD before hdd, but I will try to reset.

 

[Asdfggg]

How do you short the jumper?

 

[Asdfggg]

I got it to go past logo, but now it says can't detect hdd, and CD drive, the CD drive has lights, it can open, and spins the CDs, could it still not be connected correctly?