|It won't be the CMOS battery. |
As given, check all connections, including those to the monitor. Often a tiny movement of a card can cause it to move its edge connectors onto an area with oxide on it (about invisible). Clean you graphics card edge connectors with a soft pencil eraser then pop it in and out a few times to ensure the oxide is cleared off the socket too.
Same can happen to any edge connectors including RAM and SATA HD power and signal connections.
You have posted on XP forum but your specs say Win 10 - which is it?
Always pop back and let us know the outcome - thanks
message edited by Derek