How old is the PC? Is it still under warranty? What security/antivirus software do you use? Do you turn it off at the end of the day? If not, you should.

The attached link will give you more information. In the meantime, here's what I would do if my PC crashed periodically--

-Open the case and CAREFULLY (without making contact with the components) vacuum away any dust

-Delete all caches and history from all browsers

-Run Disk Defrag/Optimize

If these don't seem to help in time, I would consider a cleanup with Malewarebytes and changing to a different antivirus program if not using one of the better ones. As a last resort, backup ALL your data, photos, music, important files, etc to an external drive and then run a Recovery process. Doing that erases the hard drive so that all software and files you want to keep need to be put back on again. A fresh start might fix the problem if caused by bad drive sectors or corrupt files.

PC Crash causes

Did you check your settings, do you have it set to shut down after oh say 25 mins. or so? always check your settings first.

What setting causes a PC to crash and then restart?

Every once in a while my computer will just close down and restart?

Do you ever see the hint of a flashing blue screen?

Some computers are set to automatically restart after a blue screen. The blue screen can fly by without seeing it. There is an option to disable auto restart on system crash (Blue screen) so you can read the blue screen, but I think it's a lot easier to just run Whocrashed

We should verify if it's blue screening first by running a simple program called whocrashed.

Lets see if we can see what's causing the [color=blue]Blue Screen[/color]
Download Whocrashed from here-> http://www.resplendence.com/downloads
This program checks for any drivers which may have been causing your computer to crash....
Click on the file you just downloaded and run it.
1 Put a tick in [b]Accept[/b] then click on next.
2 Put a tick in the Don't create a start menu folder then click Next.
3 Put a tick in Create a Desktop Icon. Then click on Install and make sure there is a tick in Launch Whocrashed before clicking Finish.
4 Click Analyze.
It will want to download the Debugger and install it Say Yes.
WhoCrashed will create report but you have to scroll down to see it.
Copy and paste it into your next reply.

Also

Windows logs most events, so you may look in you event log for other clues.

Google--> open event log win 7<---- Problem with that is there a pain to read.

Post the whocrashed log

Is your computer set to Automatically Update. I've had my Computer Restart after Minutes and Sometimes Hours, to apply Updates that were Downloaded and Installed. You should receive a Warning, but I've noticed that I don't always receive a Warning. This has happened to me a lot since the Windows 10 Upgrade, but I've had it happen in other Operating Systems too!

Zep516 is right, if your computer is crashing (as you've posted) you should have a BSOD (Blue Screen of Death). Sometime the Blue Screen is set to Restart and the computers these days are just so quick your lucky if you see a Flash of Blue when it happens. As Zep stated, there is a way to Turn it off, but you may as well just use Whocrashed!

If it were me, I'd check to see when Updates were Downloaded and Installed, then use this information to check against the times your computer has restarted seeing if they match (that is, if you can remember the approximate times your computer restarted). You could also Turn Off Automatic Updates and see if this Crashing (Restarting) Continues!

Agree w/bugs -- automatic W10 updates that occur while my machine is in "sleep" mode cause it to become unresponsive (won't wake up). Restarting it from the power button is necessary, but then everything is OK & the update "takes". So, at least in my case it's an annoyance but not a real problem.

I apologize for responding at such a late date. I have been away on a personal matter. When the pc shuts down, there is never a blue screen. It just shuts down and restarts. I have used the whocrashedme app and it never shows anything. It could be as others have said, updates installing. It hasn't happened in a while now so I have my fingers crossed!

Microsoft usually releases Most Updates on (I think it's) the Second Tuesday of every month. This doesn't mean there won't be any other updates during the other 28-30 days. Updates don't always require a Restart. You should be getting new updates on or around the 10th of January.

I have Windows 10 on my Laptop and it got 6 Updates on the Wednesday the 14th of December. I may not have had it Turned On, on Tuesday the 13th (or may have sut it down before they installed). I did have one other Update on the 9th of December.

Keep an eye out on January 10th to see if you get Updates. Then keep a close eye on whether or not you computer Shut Down or Restarted around this time. Like I said though, the computer doesn't always need Restarted!