I am trying to boot an older PC running XP and when I power it up, I immediately get 3 long beeps and then the cd drive powers up. I don't get the post beep, video or even keyboard power. I have tested the PS and it shows well within range. I have made an xp msdos boot disk and it doesn't work at all. I put in my xp cd and it spins but doesn't work either...Where should I go next for testing? Thanks