A few days back i had a very bizarre crash(/freeze up) with my windows 8 laptop and i am trying to diagnose the cause. This was the most complete freeze i have ever had yet there were no programs running at the time, i would like some advice on finding what caused it and what went wrong. I couldn't find any logs of it but i am not sure where one would look for them anyway but below i have a ful description of what happened.
on 12/08/2014 at 1820(ish) i logged off from the admin user account on my machine and left it logged off, but not turned off to return to it later. sometime between 1835 and 1840 i returned to it and shook the mouse to "wake it". as usual upon doing this the "background image" i use on my lock screen was displayed but the time/date/battery state/wifi status icons usually shown on the lock screen were not there. to bring up the "page" where i input my password i would usually use the down arrow but pressing the down arrow gave no response, i then tried the "esc" key, no response. "ctrl"+"alt"+"del" gave no response. pressing and holding down the power button to try and turn it off gave no response. I also tried removing my usb mouse, which when plugged back in (as removing it had no effect) the cursor no longer responded to the usb mouse. with n responses from pressing and holding the power button i was forced to shut it down in a brutal way by physically removing the battery. after a minute or so with the battery out i re-inserted it. usually i am able to start this laptop just by lifting the lid but this time i had to press and hold the power button to turn in back on after the "hard shutdown". it took a while to load but eventually showed the normal lock screen and i was able to log back in and use it in the normal way. The weirdest thing is that before logging off(at 1820) i had not been doing any "heavy usage activity"(rendering 3d models in blender, etc). all i had done before logging off was watch some online videos and then watch an avi video(from my harddrive) with vlc. a scan with malware bytes after this crash found no signs of any infections, neither did a few other scanners i used, a look in "event viewer" wasn't very helpful. i don't really understand what event viewer does exactly but i was able to find a stored error "note" complaining about the "hard restart" i had given it but no error notes describing what had caused the freeze. the only things i had done earlier(a few hours before the 1820 logoff) were connect to wifi(a network at a friends house which i know to be a clean and trustworthy network, and which i have used 5 or 6 times in the past) where i usually use a wired connection and plug in a new pair of headphones i had bought that day. what on earth caused this crash? hardware damage,software damage,the processor struggling to run some "heavy usage thing"(i can't think what when the computer was logged off),a really sneaky virus, some sort of messed up business with the new headphones, something caused by the wireless connection? also how can i find the cause?
for some details the computer is a toshiba satelite pro L850. my version of windows is windows 8(i don't know whether it is the normal or pro version but i suspect it is normal), 64 bit. it is fully up to date but i had not downloaded or installed the 12th august "patch tuesday" updates until a few hours AFTER the crash. the wi-fi network i had connected to that day was a "wpa2-personal" type of network for which i input the password from my machine (my friend told me what it was). the new headphones i had bought that day were "logitech h110 stereo headset" with 3.5 mm plugs to connect it to the computer(it couldn't have tried to install a driver could it?) to replace an ageing pair of "andrea NC-181 VM USB headset" usb based headphones. the video i played before logging off was an avi video of 1 minute length, played with "vlc 2.1.3 rincewind" which i have played several times before without trouble. if you want any more details i can provide them.