I have disabled windows update before starting to mine ETH with 4 cards (2060s) and this setup have been running for a week now but since two days this PC will shutdown and restart by itself
Gigabyte mobo with 8gig ram installed and power supply is 1200watts, what and what is next to check?
I assume you are using Windows 10,I suspect you haven't completely disabled Windows Update and only through group policy you can completely disable Windows update beside that services.msc everyone else uses.Follow these steps:
1.Open up Policy editor by typing Group Policy in the search menu of Windows
2.Go to Computer Configuration,Administrative Templates,Windows Components and then Windows Update.
3.Configure all these settings you see in the picture below.
I doubt there is overclock more than you should because you said that the rig worked one week without problems.And if Windows Update is turned on that may have installed a not supported driver for the cards causing these restarts.