Windows suddenly won't shutdown/reboot! Help.

[Mugsy]

Briefly: Suddenly, my computer (Win7 64bit, home built) won't Shutdown or Reboot. Two nights ago, I shut off my PC to go to bed. Everything appeared to shutdown normally (Windows says "Shutting down", pause, screen shuts off) but two hours later, I noticed the PC was still on. I had to hard power-off by pushing/holding the Power Button.

Same thing last night, and checking this morning, I discovered it won't soft Reboot either (I must hit the Reboot button on the PC to do so.)

Even if I try to Shutdown/Restart from the Windows Login screen before most start-up apps even load, it does this.

I didn't install any new hardware or software. The ONLY thing new in that time was that I purchased a new Win10 tablet from BestBuy which uses the same WiFi network and can access the Shared Files/Folders on my PC. So I'm thinking maybe my PC is looking to disconnect from a computer that's no longer there?


Stuff I've tried:

I booted into Safe Mode, and was able to Shutdown just fine.

I booted into "Safe Mode with Networking", and was also able to Shutdown just fine.

I then tried using "msconfig.exe" to disable ALL running Services and Startup apps. It didn't make any difference. Computer still hangs.

I did a full AV scan using Avast Free AV, MS Security Essentials, Kaspersky TDSS Killer, "Malware Bytes", and even checked for installed background tasks using "HiJackThis". All say everything is fine.

My problem is identical to the problem described in this thread, but the solution doesn't apply to me (I don't have anything RAID related, and I already have SP1 installed.)

Any help is appreciated (and yes, I've scoured Google.)

System Details:

I built this system myself over three years ago. It runs rock solid and is well maintained, running Cleanup software (IOBit Adv Sys Care 10) once a week. All drives scanned for errors.

64bit Win7 Home (OEM) fully updated.

Intel 4770k water-cooled overclocked to 4.3GHz.

Gigabyte Z87X-UD4H motherboard.

16GB Corsair 2133Mhz DDR3.

C: drive: 120GB ssd
D: drive: 2TB Barracuda.

Thx in advance.

 

[Mugsy]

<grumble> Okay, for future readers, problem solved (I hope).

Since the only suspicious difference between the computer acting properly *without* the video card driver vs *with* the driver was my UPS reporting "Hibernation Mode disabled", and knowing the computer will Shutdown/Reboot properly from both Safe Mode & Linux, I shifted my attention to my UPS (Battery Backup.)

The UPS Backup software does not run in Safe Mode nor in Linux, so (as mentioned previously) I tried uninstalling it but it didn't help.

Overnight, I thought about how the UPS also plugs into a USB port to control that software, so this morning, I tried unplugging the USB cable... not from the back of the computer but from the back of the UPS itself, and suddenly Shutdown/Reboot worked again!

Curious, I plugged the cable back in and the problem did NOT come back. :/

Here is what I *think* is going on: While the cable connecting the UPS to my PC is USB on one end, the other end (that plugs into the UPS) is an RJ45 ("Ethernet") type connector (weird, I know). About 6 weeks ago (2 weeks before the problem started), I had to replace the batteries in my UPS which meant unplugging everything, and near as I can figure, the RJ45 connector must not have been plugged in just right, and unplugging/replugging that connector allowed the computer to communicate properly with the UPS. With a bad connection, something was probably telling my computer to "stay on" until some "backup" activity had completed (I'm guessing.)

Now, with the RJ45 plug reconnected properly (again, I'm assuming), the PC and UPS are communicating properly and the computer once again can shutdown/restart.

Argh! I hate when stuff like that happens! I'm just glad everything now appears to be fixed (fingers crossed.)