I was running Windows 7 for a long time with no problem. It would sleep and wake up just fine. One day, it would not go to sleep any more. I never got to fix it before upgrading to Windows 8. After upgrading, the system still would not go to sleep. I did some research and basically found using the Powercfg command tells me what devices are requesting power, and updating drivers. I was able to finally get my system to go to sleep again, but now when it wakes up, it only powers on. It does not seem to POST, so it does not appear to spin up any of the hard drives or get anywhere close to booting the OS. Any ideas what else I can check? My system was designed for Vista, but ran just fine with Windows 7. I don't know if there are Windows 8 drivers for any of the motherboard components. It is a HP Paviliion Elite m9000t. Thanks in advance!