Without any indication in the event log of something gone wrong besides an unexpected shutdown, that usually means the issue is not software/windows related.

A quick point I would like to make is not to flash a bios on your system until it has been returned to a proper working state. You could end up locking it up in the middle of the flash process, and that would not be a good thing to have happening.

I am leaning more towards a hardware issue, because you said you had to unplug the system and wait for the ethernet adaptor to stop blinking.

It could possible be a USB issue, because some USB ports stay powered up even after a regular shutdown, to charge mobile devices. I have experienced this myself, where a device charging caused the USB port to get overloaded and lock the pc up.

A few things you could try: 

- Unplug the ethernet cord and see if the computer still locks up after some time.

- Unplug all USB devices except keyboard and mouse, and see if the issue still happens. I had this happen some years ago to one of my systems, were a USB device was locking up the PC and it would not restart unless I did what you did.

- Run the R11 hardware diagnostics: hardware diagnostics 

Forgot to add there's another thing you could try: Your power supply should have an LED light that should be lit up green. You can check when it locks up to see if it is green. I also think there's a small test button next to the LED, that you can press to perform a self test on the power supply. That should also return a green LED light.

Thanks for the response.

The green light next to power cord is on now. I don't know if it was on the last time the freeze occurred. I make sure to note the status of the light the next time a freeze occurs.

Given that the freezes are somewhat far apart (usually 1 to 2 weeks) some of the other suggestions will be difficult. I don't really want to run the system with just a WIFI connection for that long as it is way to slow on WIFI.

I will try to unplug some of the USB devices and see what happens. Currently the list of USB devices includes one hard drive, one solid state drive, one label printer (DYMO 450) and a USB hub with 2 memory sticks and connectors for my iPhone and iPad. Again, given the fairly long period of time between freezes this will take some time as I'd like to unplug just one or two devices at a time.

I will also run the full set of hardware diagnostics. I did previously run the short version of tests and nothing was found.

I would start with USB devices first, as that will affect usability of the system the least.

These kind of issues are the toughest to fix, because of the time period between occurrences.

Do keep us informed on the status, and hopefully in a few weeks you have narrowed down the issue.

Each time the system has frozen I have checked the event log for errors and do not see anything at the time of the freeze other than the unexpected shutdown when I press the button to power off the system.

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Easier to see in Windows Reliability Report. Look for critical (red) entries.

Without any indication in the event log of something gone wrong besides an unexpected shutdown, that usually means the issue is not software/windows related.

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True. Well used to point to bad hardware or power, right?

Well, lately ... I've seen bad Nvidia drivers cause it. Just a theory, but I thought it might be because the system has the on-board Intel GPU that stays active .

I checked the Reliability Report and the only critical events that show up the last 2 times the freeze occurred are the unexpected shutdowns when I turned the system off to get it restarted. One of these occurred on 4/14 and second one on 4/23.

1. I believe the drivers for GeForce RTX 2080 Ti in my system are now current. They were not at the time of the last freeze.

2. The current driver version date is 1/21/21 and the version is 27.21.14.6137.

3. The RTX2080 is the only display adapter that shows up in device manager on my system.

4. Is there a way turn off the on-board Intel GPU?

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1. OK, good. However, the latest driver is not always the most stable one.

2. Yes, keep notes. What driver, when did it crash, what was running, etc.

3. Then it sounds like your version of Intel main-processor DOES NOT have a baby integrated GPU. You would see it there.

4. You can disable in Device Manager, but it's not recommended, AFAIK.

If you do suspect it could be related to an issue with Nvidia drivers, you could give the Nvidia studio drivers a try.

These will not be up to date on the latest game profiles etc... but they have been extensively tested against various applications and they are all about stability and reliability, and less about cutting edge support. You might end up with less gaming support, but you can be ensured driver stability.

You can download them directly form Nvidia: Nvidia studio drivers 

Please note these do not support RTX 3000 series. Only 2000 series and below. Since you have a 2080 you should be good. Yes, these are the latest studio drivers.

Also something else you could try: R11 freezing 

It seems other users have reported great success with it.

Yes, it is always good in situations like this to only do 1 thing at a time. Otherwise you might introduce issues.