PC reboots during idle, no warning, no apparent reason

[Vax]

So...I am usually pretty computer savvy, but this problem has me at wits end...I'm not sure what else I can do other than ask someone because I have tried most anything I can think of.

Let me do a run down:

Problem: Random reboots
Began: About a week ago
Additional info: It all began when I left my computer off while I went to pick up my daughter from school. When I came back home I saw my computer was on the initial start up screen. I pushed space to bring up the log in request, logged in, and expected that it had just locked itself like I asked it to do when it went idle.
Turns out that it had actually rebooted. It brought up the apps section and I took it to desktop, thinking nothing of it...Perhaps one of the cats stepped on the power button? Those damned hairballs always jump up there cause it's nice and cozy.

Well a few hours later I come back, and I see this picture(Minus the text in the top left, this is a pic from Google)

I got a little worried, but left it there with the 0% for I don't know how long before I decided to simply push the power button and force a reboot manually. It started up no problem, happy as can be, and displaying no error messages.

I continued with this problem since it only seemed to happen when I wasn't at the computer at all(I.E no writing or using Firefox or player a video game or anything)So it wasn't really that huge of a bother.
Until it did it during Netflix.
Now I'm a man of patience, and if there's a problem that doesn't affect me directly? Then I don't see the problem in trying to fix it, let a sleeping dog be as I always say, but when that error interrupted my Netflix right in the middle of it? Then it became my problem, and I went on the warpath.

I discovered, and tried, the following troubleshoots:

1) Went into start up options through control panel and set the Memory dump to small(256kb).
2) Went into start up options through control panel and unchecked the reboot automatically box.
3) Refreshed(Not restore)my PC.
*4) Rebooted into Safe Mode, and did a Virus Scan from safe mode.
5) Updated AMD drivers as recommended by the AMD website.
6) Updated Microsoft Windows as recommended by the automatic update.
7) Updated my graphics driver to most recent version.
*8) Took the side panel off of the tower and unplugged everything, then replugged it.
9) Ran a Windows Software troubleshooter(It came up clean).
10) Restarted my computer under normal, average circumstances several times.
11) Opened the case to check for dust layers(Almost none), and sprayed it from top to bottom with canned air to remove whatever dust there may have been.
*With this problem? I highly, HIGHLY advice you to 'not' boot into Safe Mode! I used the Windows Key + R keystroke, and typed in msconfig, then I went to the Boot tab, found Safe Mode, checked the box, and rebooted my PC. It never came back up, and only through my laptop did I find the idea to unplug all hardware(Not the plug in the wall, but the actual computer internal hardware) and replug it. This fixed it and allowed it to boot into Safe Mode. However, it didn't work, so don't bother trying!

Finally, after trying almost anything I could possibly think of, I sat down after the Norton Scan was finished, rebooted into normal Windows 8, and went about my business. As I was watching Netflix on my Laptop(To avoid potential interruption), it did it again.
As always, there was no warning signs, no funny sounds came from the computer, the orange activity light on the front never flashed once, no 'hanging' 'freezes' or 'doesn't respond' errors. There was utterly nothing to show when it was going to happen.(Again, this 'only', and I stress 'ONLY' happens when I am not using the computer..When I do use it, I can be on it all day 16 hours straight and nothing happens...Leave it, however, and eventually the screen turns blue with the shown screen, within 5-15 minutes. It never happens after the exact same amount of time)

I have realized that my computer sometimes seems a little slower, and Firefox does sometimes experience a few hangs and mild freezes, but they never last more than 15-20 seconds at the very very most, and my computer does sometimes seem to struggle(The yellow working light sometimes remains turned on for several minutes at a time instead of doing the signature 'flashing'). This was why I decided to do the Safe Mode virus scan, to make sure it wasn't Malware, Spyware, or something worse that was causing the lag/random reboots/blue screens. As mentioned, the Full System scan came out clean as a whistle, meaning this is not a Viral issue.

I have tried literally everything, and I don't know what else to do anymore. Any help, insight, suggestions would be fantastic.

(I know about how Power Supply / RAM issues could be the culprit, but I shall not and will not spend a single penny on fixing this if it can be done for free. Besides, I could replace both Power Supply and RAM chips, but if that wasn't the cause, I'll remain at 1 problem to solve, and $60-$100 poorer than before, without solving anything for it.)

My DxDiag for your review

 

[Astralv]

I would say- Ram/Power supply. Sorry- you did not want to hear it. lol. Thanks for the nice read- I like the hairball cat part the most. 2 of my computers doing the same thing, mostly when I am not here. It was happening often when I just built it but with time I see it less. My other thought would be that it has something to do with Sleep/awake modes. What motherboard do you have? I have Asus on 2 builds and both had this problem. I also had problem of them not waking up. I resolved that, and now after updating to 8.1, it would not go sleep. May be you should update to 8.1, then it would not ever sleep and ever restart...

 

[johnbl]

window 8 and 8.1 have enabled more power saving features. This exposes bugs in drivers and in the firmware of various electronic devices. I suspect the OS is telling your hardware to enter a low power mode and the driver or device itself is bugged. I would test this by using control panel and telling the os to not enter power saving mode. just high performance. if the problem continues then I would look for other problems. if you don't reproduce the problem on high performance setting then you will want to debug the problem as a sleep/wake/low power issue

also if check your event log for a bugcheck entry. there should be one if the log could write to the disk at the time of the bugcheck.

 

[Vax]

Thanks for the responses guys! \o/

I actually did do a check on the bugcheck entries, and I googled what they claimed. Nothing of any use came up about it, just the usual do a troubleshoot and that should fix it bull from Microsoft.
What I have not tried yet is update to Windows 8.1. I checked the list of new additions you'd get with it, and no where did it claim to improve on bugs, just more of the 'NEW AND REVOLUTIONARY TOUCH SCREEN APPS BULL JUST 4 U MY FRIEND!' speech that they seem to love to pitch nowadays.

I have no clue what Motherboard I have, at all. :\ And it seems that only 3rd party software can tell me, but I'm not exactly one to trust scanner software that isn't from a company I know(And I know most of them).

 

[Astralv]

What computer make? What year? I may be missing the specs somewhere...

 

[johnbl]

msinfo32.exe comes with windows and display various info about your machine. in particular look at system manufacture, model number, bios version...

a good bugcheck file is very useful you run whocrashed.exe on it to get a good idea of the root cause. often updating the offending driver is all that is required. failing that, the crashdump file can be placed on the cloud and someone can look at it with the kernel debugger and use the automated debugging commands to find the issue. if you have your system set correctly microsoft windows error reporting will report your crash to microsoft and they will roll out fixes in the updates

 

[Vax]

What computer make? What year? I may be missing the specs somewhere...

The computer make is Hewlett-Packard Envy h8-1414 Desktop PC from I believe 2012ish I bought it less than a year ago(Hense warranty is up) I bought it shelved at Best Buy in Oregon for $520(On clearance sale)

I am looking around in that msinfo32.exe thing that johnbl proposed, and I'm seeing a Base Board thing. It says that the Manufacturer is Gigabyte, but the BaseBoard name is unavailable.

My Windows 8 version is 6.2.9200 Build 9200.

That's all that I could really come up with.

On another note, I decided to try and simply put my computer to sleep mode manually before I left the PC...That worked well once...On the second try when I tried to wake it by tapping any key, the computer turned on(I heard fans whirling etc. inside) but the screen remained in dormant mode. My mouse responded(Not on the screen though...It has lights, and the lights were on)while my keyboard showed no signs of life at all.
I tried to unplug and replug components more than once to fix it, and finally, after force shutdowning the computer with the power button more than 4 times, it booted......From sleep mode :\ I turned the computer off, and UNPLUGGED its power twice...And it still boots as if it had just been a sleep?.....

I'm mildly confused about the nature of this problem at this point...I can't find any issue quite like it online.

 

[johnbl]

I would update your chipset drivers, and bios to the current version as a start.
http://h10025.www1.hp.com/ewfrf/wc/softwareCategory?os=4132&lc=en&cc=us&dlc=en&sw_lang=&product=5296859#N1034

sounds like one of your hardware device goes in to a low power state and does not transition back to a high power state. This can happen for many reasons, bugs in the BIOS, bugs in the chipset drivers, or actual bugs in the firmware or electronics of the devices themselves. First thing to do is update the BIOS and chipset, if the problem persists then you have to isolate the cause. Generally, you isolate the cause by using device manager and turning off power link states or sleep properties for the individual devices or run powercfg.exe /energy and look at the report to give a hint at which device has the issue. Some devices like SSDs or some cdrom will have firmware you can update to fix your problem but sometimes you can not fix the issue and just have to disable the low power state for that device. (I have had to do this with some older hard drives that could not be fixed) Some people don't want to deal with the issue and just disable all the sleep/ low power states and just set the machine to high performance and enter sleep manually (make sure your BIOS is not set to turn off your USB ports on a timer and that you have selected a wakeup method in your BIOS or you will not be able to wake up the machine with a keyboard, I have my BIOS set to wake when the space bar is hit on my keyboard.