Quite high spec home built PC won't install Windows 11

[babysnakes]

My rig.
Asus Crosshair VIII Hero (WiFi)
BIOS: 3801 (TPM version 2) Switched on , Secure Boot on
CPU: Amd 5950X
32 GB G-Skill Trident Z (DOCP) enabled 3600
MSI RTX3080 Suprim 10G

Every time i try to update to Windows 11 (this has happened since the Insider Build ... not sure which one) ... normal blue screen, Windows is updating, it goes through it's normal (but quite fast installation) then reboots to Asus BIOS. Within seconds the BIOS says "Attempting to undo any changes" ... reboots & i'm back in Windows 10.

Any ideas?

 

[Garyw]

Sometimes update failure is caused by problems in your current O. S. Run a Windows Defender Offline Scan and a Malwarebytes scan. Then open a Cmd. Window as an administrator, and run "sfc/ scannow". If it doesn't find any errors, run it again. If it finds and fixes errors, keep running it until it reports no errors found. If it finds errors that it can't fix, run "DISM /Online /Cleanup-Image /RestoreHealth". Also error check your system drive. Please report back the results.

 

[babysnakes]

Hi Garyw, thanks for the reply, i've done all that already. Also got in touch with Microsoft who said upgrading via Windows Update is a notorious fail. Tried installing from the Windows website using the Windows 11 Installation Assistant as suggested by Microsoft also with Bitdefender disabled and did get further, but it still rebooted into BIOS & undid any changes.
I may well just hang on a while now.

​

 

[Edwrd10]

1- Check your Hard drive to see if it is in MBR Mode or GPT mode. Win 11 requires GPT mode to run 'Secure Boot'.
Go to disk mamagement and right click on the left side that gives the disk drive letter and if MBR is dull and GPT is highlighted then its in MBR mode. Opposite its in GPT mode(Which is what you want). If in MBR you have to install Win 11 from an ISO image which you create with the win 11 media creation tool, https://www.microsoft.com/en-us/software-download/windows11, second option down.
2- Create an ISO onto a flash drive 8GB or more. Go to UEFI(BIOS) boot menu and tell it to boot from the flash drive. save changes and exit. PC will reboot into Win 11 ISO setup. At the beginning there should be an option in one of the menus to select GPT or GUIDPT. Then continue the full install. The ISO will give more options at the beginning of the install than the upgrade will. Good Luck!