Hi David. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.
You said you have it set to Sleep Never, but that it turns off. Are you saying it actually shuts down to where you have to power it back on, or is it possible it's suspending in some other way. If this is not what you are asking then please clarify.
If so, Let's take a look at all places where Windows can suspend to try to find the culprit:
- Check closely your Display, Sleep and Hibernate settings in Power Options following this guide: https://www.tenforums.com/tutorials/2843-change...
- Display timeout has been moved to Settings > System > Power & Sleep > Additional Power Settings, on active Power Plan choose Change Plan Settings then adjust Display timeout.
While there check also Advanced plan settings > Sleep > Allow Wake Timers > under Battery & Plug In options set to Enable, Apply, Save.
- If your Power Options settings are set correctly then the next suspect is the screensaver which is mysteriously setting a 1 minute timeout to blank Screensaver when some Themes are chosen. Check that now at Settings > Personalization > Lock Screen > Screen Saver Settings.
- This could also pertain to an issue of Unattended Sleep Timeout setting in Registry. See the Marked Answer here for what has worked for others: https://answers.microsoft.com/en-us/windows/for...
Whenever modifying the registry, first set a System Restore point: http://home.bt.com/tech-gadgets/computing/how-t...
- If System Unattended Sleep timeout is not present here's now to access it: https://www.tenforums.com/tutorials/72133-add-s...
- If you suspect overheating which can shut down the PC, then install CoreTemp to monitor temps from System Tray:
https://www.thewindowsclub.com/core-temp-monito...
https://www.pcworld.com/article/2365089/compute...
- Since sleep is overwhelmingly controlled by the Display driver, Update the Display driver from the PC or Display adapter maker's Support Downloads web page for your exact model number, HP Serial Number or Dell Service Tag - from the sticker on the PC.
While there check also for newer chipset, BIOS/UEFI firmware (very important), network, sound, USB3 and other drivers, comparing to the ones presently installed in Device Manager reached by right clicking the Start Menu.
if this doesn't give you the latest or ideal driver for what you need, compare it to the driver offered by the Intel driver update Utility here: http://www.intel.com/content/www/us/en/support/...
or the Nvidia Update utility here: http://www.nvidia.com/Download/Scan.aspx?lang=e...
or the AMD autodect utility here: http://support.amd.com/us/gpudownload/windows/P...
For Display issues one fix that is working is to Roll back or Uninstall the Driver on the Display Device > Driver tab, restart PC to reinstall driver.
You can also try older drivers in Device Manager > Display device > Driver tab > Update Driver > Browse > Let Me Pick.
Then you will know you've tried everything in addition to Windows Update drivers.
- Check over these other working Sleep solutions which may also be involved:
http://www.makeuseof.com/tag/fix-windows-10-sle...
- Do you know when this started? See if you can System Restore to a point before the problem started:
https://www.windowscentral.com/how-use-system-r...
System Restore is your first line of defense and can take you back to a point before a problem began like a time machine. If it doesn't help then you can undo it. Read about it first in the tutorial above and then try restoring to just before this started. If System Restore is not enabled on C drive do that now so it's available in the future.
If the problem repeats or System Restore doesn't work then check which Windows Updates were installed at Settings > Update & Security > Windows Updates > Update History, uninstall them there or System Restore again, then immediately check for and block the Updates with the Hide Updates tool explained here: https://www.tenforums.com/tutorials/8280-hide-s...
- If no power setting is causing this then go over this checklist to make sure the install is set up correctly, optimized for best performance, and any needed repairs get done: http://answers.microsoft.com/en-us/windows/wiki...
Start with Step 4 to turn off Startup freeloaders which can conflict and cause issues, then Step 7 to check for infection the most thorough way, then step 10 to check for damaged System Files, and also Step 16 to test a new Local Admin account. Then continue with the other steps to go over your install most thoroughly.
- If nothing else works then do a Repair Install, by installing Media Creation Tool and then choosing to Upgrade Now. This reinstalls Windows while keeping files, programs and most settings in place, and is also the most stable method to advance to the latest version. http://windows.microsoft.com/en-us/windows-10/m...
Based on the results you post back I may have other suggestions if necessary.
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