Windows 10: PC starts after shutdown again and again

I have this problemalready for years where when i shutdown my pc normally it will turn itself on after 3 seconds and boot up, the only way to shut it down is to hold the power button and force it to shutdown, that way it stays turned off. which is obviously not the best thing to do previously on Windows 10 i could disable fast startup feature in Power option settings which fixed the issue, the pc would shutdown normally and not boot up again. Now since Windows 11 forcefully installed itself without my consent, the feature to disable fast startup is not there anymore, i also tried the regi

:)

 

My pc takes for ever to shut down when i restart

Suggest cleaning up your startup list .There may be many services / Apps you can remove on startup which is not needed on boot or during shutdown.
Before you shutdown the Pc check what is running in Task Manager as a program or service in not killing the process on shutdown

Would suggest cleaning up running apps and services -Autoruns, StartupMonitor,HighjackThis,
Malware Scan - Malwarebytes,ADWcleaner, Combofix

 

After Windows 10 update, PC con't start

Good news, pc is back and running.
zBook was on the right track in that the BIOS was corrupted. However, the solution suggested did not work.
Fortunately, after considerable digging, I found some information on the Gigabyte site. Following their suggestions, I was able to restore the primary BIOS from the backup BIOS. The whole process took less than 10 minutes.
Basically, I had to:

1. Shut off the computer. Unplug all connections to the motherboard except the VGA/DVI output and the keyboard.
2. Press the POWER button and HOLD it. The computer will start and then shutdown. After the shutdown, release the POWER button.
3. Press and release the POWER button. The BIOS will go into recovery mode. A BIOS recovery screen will appear and you need only to select from the options that are presented.

This was a simple solution and I am now up and running.
Thanks to all who provided suggestions.

 

PC is Suffering Unexpected Shutdowns

Most important detail to me would be whether these shutdowns are sudden, in which case it's likely a short or PSU issue (capacitor aging maybe?) or graceful windows style shutdowns, which suggests software interference.

It could also be overheating components if it's a sudden shutdown. What are your thermals like?