Windows only boots into BIOS if Secure Boot is Enabled but Secure boot keeps reverting back to enabled.

[friendlyJai]

I recently formatted and reinstalled Windows 10 on my friends laptop. In order to do this I had to convert the GPT to an MBR as would not install otherwise.

To get it to boot from the disk to install Windows I disabled Secure Boot and enabled CSM. However now secure boot keeps enabling automatically and Windows will not boot but goes straight to the BIOS until I disable it again.

I read somewhere that being an MBR might be part of the problem. But as I said I had to convert it to an MBR for it to install. Would converting it back to a GPT solve the problem? Would converting it cause me to loose everything that ive just installed on the Hard Drive?

Thanks in advance
James

 

[SkyNetRising]

Your installation media probably was compatible with CSM/legacy install only.

Either convert to gpt using mbr2gpt utility or reinstall windows in UEFI mode.

 

[friendlyJai]

Your installation media probably was compatible with CSM/legacy install only.

Either convert to gpt using mbr2gpt utility or reinstall windows in UEFI mode.

Yeah, I never had any problems with the same disks on a different computer. However after reading up someone suggested that it might be because the drive was partitioned first. Although I did convert it to an MBR, which appeared to wipe all the partitions first although something may still have been there.

I also read the following link https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-setup-installing-using-the-mbr-or-gpt-partition-style and it says the following :

When installing Windows on UEFI-based PCs using Windows Setup, your hard drive partition style must be set up to support either UEFI mode or legacy BIOS-compatibility mode.

For example, if you receive the error message: “Windows cannot be installed to this disk. The selected disk is not of the GPT partition style”, it’s because your PC is booted in UEFI mode, but your hard drive is not configured for UEFI mode. You’ve got a few options:

I did indeed see that message so does that mean I must have installed in UEFI mode?

So i'm obviously confused between the difference between UEFI mode and Legacy Bios mode. The latter to me sounds like its what I did i/e going into the BIOS and disabling Secure Boot etc. So does UEFI mode enable you to boot from the installation DVD without disabling Secure boot. I wonder if that option wasn't available on that laptop and therefore did not see the options.

Thanks again

 

[SkyNetRising]

You converted HDD partitioning scheme to MBR before installing windows. This allows CSM/legacy boot but disables UEFI boot.
Secure boot is UEFI feature. Since you're having problem with it enabling automatically and preventing boot, you have to:
either convert your system to be compatible with UEFI boot (use mbr2gpt utiity or reinstall in UEFI mode) or,
if BIOS allows it, disable UEFI completely allowing only legacy/CSM boot (this option might not be available btw).

 

[friendlyJai]

You converted HDD partitioning scheme to MBR before installing windows. This allows CSM/legacy boot but disables UEFI boot.
Secure boot is UEFI feature. Since you're having problem with it enabling automatically and preventing boot, you have to:
either convert your system to be compatible with UEFI boot (use mbr2gpt utiity or reinstall in UEFI mode) or,
if BIOS allows it, disable UEFI completely allowing only legacy/CSM boot (this option might not be available btw).

Thanks if I use the mbr2gpt utility to convert it back to GPT, will this also mean having to re-install Windows again? Or will everything still be there? If that's the case then that seems simple enough to do.

 

[SkyNetRising]

If mbr2gpt succeeds with conversion, then nothing will need to be reinstalled.

 

[friendlyJai]

Brill, ile get her to bring laptop next time and convert it then.

Thanks for all your help