For some reason, my computer won't Shutdown or Reboot when I do either from Windows. It'll go through the entire shutdown process... exit Windows, say it is "Shutting down", the busy icon spins & stops, the screen goes black, but my computer stays on, forcing me to use the buttons on my PC to power-off or Restart. I discovered this after shutting down for the night only to find it still on the next morning. As a test, I tried it from Safe Mode and Shutdown/Reboot works just fine. I also tested "Safe Mode with Networking" in case it was a network issue, and that works too. I've tried disabling every Service and Startup app using Msconfig, but it didn't help. I even tried disabling the two Devices disabled in Safe Mode (my Battery Backup and a "VMWare VMCI Host device") and it didn't help. I've done multiple AV scans using Avast, Kasperski's TDSS Killer, Bitdefender (online), Eset AV (online) and Malwarebytes. None of them found anything wrong. I checked the Event Viewer logs. No errors are reported during shutdown. My Power Profile is unchanged from before (never turn off screen or power down drives when plugged in.) My system has run fine for years. The only thing "new" recently was that I bought a brand new (not used or Refurbished) Win10 tablet the same day this started and used it to access the Shared Files/Folders on my Win7 desktop. By the time I realized I was having a problem, any Restore Points from before the problem started had already been lost (the scourge of having a small 120GB SSD as my C: drive.) I backed everything up then tried restoring an old Backup from last July but ran into trouble (Windows refused to boot) and had to put my current config back. I tried to do a Repair from the installation DVD, but it says my version of Windows "is too new" (???) to perform a repair. I also purchased a copy of "EasyRE Pro Repair for Windows 7", but it didn't resolve the problem. I've searched Google and the MS Community Support Forums. Plenty of other people with similar issues, but none of them apply to me: I already have Service Pack 1 installed, nothing has changed in my CMOS/BIOS, I've done a full check of all my drives, I ran SFC /scannow and it found nothing wrong. I'm stumped. Anyone have any ideas? TIA. Hardware: 64bit Win7 Home. Home-built PC. Gigabyte Z87-UD4H Motherboard, watercooled overclocked 4770k cpu. 16GB of DDR3-2133 memory. All MS Updates installed. Avast free AV software. nVidia GTX670. C: drive: 120GB Corsair "Force GT" SSD. Windows otherwise runs perfectly, though initially, sporadically, I encountered an unusual number of "Windows Explorer" (the desktop GUI) crashes that appear to have stopped. Not sure if that's related, but someone mentioned it in another thread while having a similar problem. Help. TIA.