Upgrade issue Computer starts up by itself

Upgrade from 8.1 twice and have following issue.
After exactly 30 minutes after shutdown computer will turn on. Checked Bios and Power management settings without luck. Reverted back to 8.1 without problems twice.
Computer never had problem on 8.1 and doesn't happen since reverting back.
I am not using Lan only Wlan to connect to router.
Windows 10 causes issue.
What could signal a shutdown system to restart every 30 minutes after complete shutdown?

Other than this issue everything else seemed to work on upgrade. I was looking forward to 10 but know I have doubts.

Upgrade from 8.1 twice and have following issue.
After exactly 30 minutes after shutdown computer will turn on. Checked Bios and Power management settings without luck. Reverted back to 8.1 without problems twice.
Computer never had problem on 8.1 and doesn't happen since reverting back.
I am not using Lan only Wlan to connect to router.
Windows 10 causes issue.
What could signal a shutdown system to restart every 30 minutes after complete shutdown?

Other than this issue everything else seemed to work on upgrade. I was looking forward to 10 but know I have doubts.

Either the PC isn't actually shutting down and is in some kind of hibernation state or a BIOS alarm or other hardware trigger is turning it on.

Maybe you have some wake on WLAN function enabled or something and there is something triggering it.

I thought of those suggestions. Hibernation was turned off and Bios settings don't indicate any alarms. It only happens with 10.
Never had a problem with 8.1 on same settings.
Bios has Lan enabled. Should I disable since I don't use it and could this be trigger?
Thanks for your response.

What's your motherboard's model number and have you checked to see if the manufacturer has released any Win 10 drivers?

Asus website has no updated windows 10 drivers or Bios update yet.
I have never seen this issue with any of the many computers and upgrades I have done.
I went to Microsoft store yesterday and spoke to a Tech who never saw this happen. Also spoke to Microsoft Call center rep and he was unable to give advise which is not surprising.

I may have found issue. Under hardware properties I opened Realtek PCIe GBE Family Properties. Box is checked that says allow this device to wake the computer.
Wifi adapter does not have box checked.
Does anyone know if this is possible problem before I try Windows 10 for third time?
I don't want to press my luck reinstalling 8.1 if it does not work.

I may have found issue. Under hardware properties I opened Realtek PCIe GBE Family Properties. Box is checked that says allow this device to wake the computer.
Wifi adapter does not have box checked.
Does anyone know if this is possible problem before I try Windows 10 for third time?
I don't want to press my luck reinstalling 8.1 if it does not work.

Your GbE adapter isn't Wifi. Unless you're plugged into a LAN, and sleeping the system, it probably isn't that. However, you could have something in your system BIOS that is triggering the boot. Check there.

Thanks.
I know the GBE isn't wifi but in Bios the Lan ethernet and wifi adapters are both enabled. Since I am not using Ethernet would disabling it in bios be a problem. Per my previous post it looks like GBE is set to wake the computer. Could a timer of 30 minutes be built in system bios looking for Lan connection which wakes computer.

Thanks.
I know the GBE isn't wifi but in Bios the Lan ethernet and wifi adapters are both enabled. Since I am not using Ethernet would disabling it in bios be a problem. Per my previous post it looks like GBE is set to wake the computer. Could a timer of 30 minutes be built in system bios looking for Lan connection which wakes computer.

Was your computer sleeping or actually fully turned off, when it would power on by itself? Seeing as we're talking only about a software difference (10 vs 8.x), it seems improbable still to be the hardware configuration.