Gone for 2 days, XP boot up stuck in loop

[Networker4321]

This machine with the problem was my second build. It's a gigabytle mobo but I don't have the box here in the house, it was a replacement while I had RMA'd the GA45-ED3P. E7500 Intel chip (1155 socket) 3.75 ghz. 4 GB Crucial DDR3 mem, same Seagate 320 GB drive from first install. It was not folding at the time but has that last GTX 560 Ti that I bought.

Now, the system shows the mobo option screen on boot. Then it comes up with the black screen for choosing how you want to boot,,,Start normally, Last known good config, Safe w/ Net, or Safe. I can't select anything but "Start Windows Normally", keyboard up/down arrows don't move the cursor ( wireless keyboard, high end Logitech and the USB plug in with the curved platform shows the normal center light. caps or scroll are not locked on.

The timer counts down from 30 and Windows XP, SP3 attempts to come up, progress bar scrolling along bottom but after 20 seconds or so I get a brief but too quick to read blue screen then it's back to the mobo screen. I will have to go to the office in the morn and get the mobo CD.

When I got home last night mouse pointer was frozen, one tab with the Weather channel and second tab with Fox News running firefox. I had to hold the power button down for 6 seconds and it DID reboot, said the sys has recovered from a serious error. This morning when I got up at six it was in this perpetual boot attempt mode. Using the mobo screen I can see all voltages are in range, all fans are OK. CPU temp is OK.

Any suggestions or need for more data? I can put the RMA mobo back in and reinstall the GTX 295 -181-B ( dual 295) but I suspect bios or corrupt OS. I have the OEM XP CD and changed the boot device to CD and tried the disk but no love, no change. This was a $2K build and add $500 for the temp mobo and 560 GPU. Got to get it back up!

Any suggestions appreciated.