Windows 10: PC restarting

My PC every now and then turns off then restarts. Please help I've had this PC for almost three years and never had this problem.

:)

 

MY PC has just statred to restart even during Boot and after boot, Please help.

if you want to change any setting just do it step by step so you know what might happen when your pc restart again and again

 

Inexplicable restarts

Thanks for your patient help and analysis, zbook. I'll step through some of your suggestions over the next few days - there's a lot to do and some look a bit hairy! That is, for a PC that is working sweetly right now...

Meanwhile, as requested in the BSOD thread (sorry, I misunderstood and posted there by mistake), I've attached both ZIP files.
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One step I did try right away was to answer your question about whether my BIOS is up-to-date. I had no success at the AMI site but did get some info from this commercial site:





It was one of the '9' (I counted 10) listed here:





Terry, East Grinstead, UK

 

PC Build Steps

Ok just because I like steps i am going to create some steps. Please give me the stamp of approval/disapproval

• Install system in case
  • Remember to connect SSD and optical to same SATA ports on motherboard
• Turn on PC
• setup HDD
• run blend test in prime95 for 30-60 min
  • run realtemp at the same time

• While in Prime95 test
  • if CPU goes above 70c in RealTemp, I have a leaky CPU
  • if my system locks up or blue screens, there is an instability in the system somewhere
  • if my system does not lock up or blue screen, my CPU is not damaged and I am in the clear!

What do you guys think??