I have an HP s3023w slimline PC with an AMD Athlon single core processor. The documentation for the motherboard (Asus M2NC51-AR) states that it can handle processors including the Phenom Quad-Core (AM2+) up to the (A) 9xxx series. I purchased the AMD Phenom X4 9850 Quad Core processor, insert it into the system, and it won't even POST. I've even moved the motherboard to a new case with a MUCH larger PS (500W instead of the 160W in the slimline case). The system still works fine with the single core, but I want to upgrade. I can't find a BIOS upgrade for this motherboard anywhere and I can't get support from either HP or Asus. Does anyone have any suggestions as to how to get this upgrade to work?