It's a different story actually. The system is crashing, only the crash is not the kind that Windows catches what means that it isn't a BSOD.
As this is a shutdown/restart crash a first step is testing the PSU, checking 3.3v, 5v and 12v values in the BIOS and making sure that the PSU is capable of providing enough power to the entire system.
Please note down the 3.3v, 5v and 12v values and post them, test the PSU and provide your system specs with as much details as possible (see my system specs as an example) so we can check it too
Please fill in your system specs
Please follow this tutorial
and download the tool. The tool will give you detailed information about your system specs, please fill in your system specs more completely including PSU, cooling and other used stuff like mouse, keyboard, monitor, case, etc.
The PSU, cooling and other stuff are NOT mentioned in the tool.
In the left corner below in your post you find 'My System Specs'. After clicking it you can find a link a little below that says 'Update your System Spec', click on this link to get to the page where you can fill in your system specs.