I have a used system.

I have a used system.
Advance 10e motherboard.
The system won't boot, there is no display and the motherboard makes an beeping alarm sound.
windows xp pro booted a couple times, then this problem.
Tried again later and it started to boot but gave an error screen, allowing windows to boot normally if I choose.
I let it try to boot normally (was the only option anyway) and looked like it was booting, but got an error screen.
Later, no boot again, just alarm beeping and no display.
What causes this alarm sound?
Could it be a ram problem?