Solved: Re: Dual boot windows and linux on Erazer Defender...

Ticket · ‎15.11.2021

This is a work in progress, so here's what I have found so far.

I have a Medion Erazer Defender P15 MD62294, MSN 30031897

An official debian or ubuntu live disc (on a USB) will boot if you press F2 during the power on process
to enter the UEFI menu and select the boot option. For this laptop you need to have a debian 12 (bookworm)
or ubuntu 21.10 live disc in order to get support for the RTX 3060 GPU. Official installers work because
they have a signed certificate to allow secure boot.
If you try using, say, the linux system rescue disk, it will not boot becuase it does not have a signed
certificate.

However, on trying the ubuntu live disc (selecting 'try ubuntu') all seemed to be working, but on
selecting ubuntu to power down, the laptop hung and no pressing of return key / esc / etc. would help.
So I pressed the physical power off button. On restarting, I was dropped into a blue screen, which said
"Bitlocker needs your recovery key to unlock your drive because secure boot policy has unexpectedly changed"

To do this, one has to go to this web site:
aka.ms/myrecoverykey
You then have to sign in using a microsoft account (your gmail account and password would do).
You will then see two recovery keys. The one marked FDV is for a 30GB recovery drive,
the other marked OSV is the 444GB operating system drive - that is the key to use.

Once you have entered the OSV key you can boot into Windows again.

It appeared to me that this problem was likely to recur, so I went about finding how to disable secure boot.
When in UEFI, there is an option to alter the secure boot settings. These settings were not available before,
the ability to edit them had become available after I had to unlock the drive.
So I turned off secure boot and restarted the machine.

I still ended up with the blue screen again, so I entered again the recovery key and got back to the windows desktop.
Although this laptop is a Windows Home edition, it still uses bitlocker for the system and recovery drives,
and it appears I now had to turn bitlocker off for these as well. I found there is no GUI option for doing this on this laptop, it has to be done using powershell.

First, I set the powersave options to 'never power down', just in case.
Then press the Windows + X keys together, and select PowerShell (admin) option.
You get a command line window. Enter these commands:
Clear-BitLockerAutoUnlock
Disable-BitLocker -MountPoint "C:"
Disable-BitLocker -MountPoint "D:"

It is advisable to wait about 20 minutes to allow the drive decryption to finish.

Then you can reboot.

You will then find that you can now boot a linux rescue system USB ( from https://www.system-rescue.org/ ) with no issues (no blue screens!)

One may argue that the laptop installation is now less secure, but I have no need to have an encrypted O/S, while I welcome the flexibility to be able to install another O/S or use a linux utility disk.

My next task will be to use a debian 12 installer to set up a dual boot windows / debian system