I just recently purchased an Asus P5K3 Deluxe WiFi board in order to upgrade my system. Along with it, I bought a Core 2 Quad Q6600 processor and 4 gigabytes of Patriot PC3-10666 memory. I have had nothing but trouble since I first put these pieces together. First, the motherboard didn't want to turn on. Then when I finally got it to turn on, the BIOS didn't recognize the processor. Not too surprising, since it was a first-release BIOS from May 2007 and Asus' website said I would need an upgrade. So I upgraded the BIOS and the motherboard was still unreliable about turning on and would sometimes freeze when I did get it to power up and boot DOS off a floppy. I manually programmed the memory settings in the BIOS setup after reading the reading the SDRAM's SPD because I suspected the BIOS was probably programming the memory settings incorrectly. I got Memtest86 to run two overnight tests (15 passes total) without incident. Problems solved, right? Wrong. This afternoon, I hooked up a SATA hard disk. The motherboard didn't want to power up at first with the hard drive attached. Then when it finally did turn on, it didn't recognize the hard disk. I powered it down, moved the hard disk to another connector. Try to power it back up again, and no response again. There's nothing wrong with this hard disk as far as I can tell - it's brand-new! Remove the hard disk, and eventually after some coaxing, it powered up again. I'm 90% sure this is a bad motherboard because it doesn't power up reliably, but when I can convince it to turn on, it runs memory tests and some simple DOS applications without incident. I've left it on overnight as I said and have come back in to find it still responding normally. I'm going to call Asus technical support first thing Monday morning about this since the seller's return policy requires that I do this first, but I'm wondering if anybody has had similar trouble with this particular board and CPU? Here are the components: * Asus P5K3 Deluxe WiFi motherboard (BIOS updated from version 0301 to version 0810 dated Nov. 12, 2007) * Intel Core 2 Quad Q6600 2.4 GHz processor (stepping G0, PCG 05A which the motherboard manual says it supports) * Two Patriot PDC32G1333LLK low-latency DDR3 SDRAM kits to produce 4 GB of RAM * PNY Verto GeForce 8400GS PCI Express x16 video card * Cooler Master 650W power supply (model RP-650-PCAR) used most of the time; have also tried an Antec 450W power supply. No change in behavior. * Memorex CD-RW PATA drive (hasn't always been connected) * Seagate 80 GB 7200.10 Barracuda SATA drive (also hasn't always been connected) * 3.5" floppy drive Anybody had any experience - good or bad - with this motherboard? I've had dependable Asus boards in the past, so this is a bit of a surprise to me. Thanks, Greg P.S. I'm not attempting to do any overclocking, water cooling, or other performance tweaks yet.