From Newsgroup: alt.os.linux.mint
On Wed, 6/17/2026 5:11 AM, Heinz Schmitz wrote:
Paul wrote:
For that, you can try "mbr2gpt.exe", and that command has strict limits
about what it will convert from MSDOS partitioning to GPT partitioning.
The "mbr2gpt.exe" takes a maximum of three partitions. It is not
capable of doing a good job converting extended/logical to GPT.
AI Overview
Converting a disk to GPT using Diskpart erases all data.
Back up all your important files first.
The command "convert gpt" in diskpart, is definitely not your friend,
as commands go. There are plenty of alternate activities you can be
doing instead. It's as dangerous as using the "clean" or "clean all"
commands.
What I found on the web rather by a coincidence: https://support.microsoft.com/en-us/topic/windows-secure-boot-certificate-expiration-and-ca-updates-7ff40d33-95dc-4c3c-8725-a9b95457578e
"... Windows Secure Boot certificates expiring in 2026"
As it seems, MS$ also managed certificates for certain linux-families.
I can't yet see to what extent we linux useres are hit and which
machines will further on operate as normal.
A discussion can be found on https://www.heise.de/en/guide/FAQ-The-secure-boot-disaster-9751994.html
Regards,
H.
Sure. This is why you've seen programs like "mokutil" being
run for you and messing around and screwing up the UEFI databases.
As long as PCA2011 is not revoked, then both kinds of shims
(PCA2011 based or PCA2023 based) would continue to work. Ubuntu
at least, may have attempted to inject something in db and dbx.
The dbx entry might be revocation of the PCA2011 one.
So yes, there are details, and they do matter, but... only if you
have Secure Boot switched on.
Two of my machines have received BIOS updates. A third machine, I
have the BIOS USB key ready to shove into that one and update it.
The BIOS update USB key has two files on it, for two different brands
of motherboards.
The latest issue, is there is some signing or certificate associated
with NVidia video cards, and (maybe) if you install a 580 driver,
it won't secure boot with an older card. Which is why you might be
using a 550 driver.
I had something tip over here, where I had to remove around 20 packages
with "NVidia" in the name, so I could get the Driver Manager to work again. Then I could select the 550 driver or so, and that installed OK and
everything behaved properly after that. And that might be with a
GTX1050 video card. This might have happened after some update session --
the complexion of things changed and I still don't know all the details.
On the one hand, you can turn off secure boot, but... I have one
motherboard here that continues to analyze Linux materials even with
secure boot off and the motherboard actually "black screens" and nothing
works for as long as "invalid" hard drive contents are present. Once
you remove all the OS drives which don't have perfect certificates and signing, then the motherboard turns on the screen again. That's an example of a
worst case. I'm typing on that machine right now, but if I plug in some
of my SSD collection, I can easily be treated to a black screen and then
I have to disconnect whatever is not compliant. An Asus motherboard
across the way, does not do that, and it behaves like a perfect gentleman.
It actually attempts to boot things, only when asked to do so and not before.
Could something happen after June 2026 passes ? Yes.
Can I escape the symptoms with some work ? Maybe and maybe not.
You should run a Google and find out what command line stuff to run
to verify whether you're ready or not ready.
If I were to turn on Secure Boot today (as the room is up to date
on PCA2023), there are probably around 50 OS DVDs here that would
no longer boot. Just to give you some idea just how important this
day is. Depending on what happens to you, you could be a not-happy user.
Paul
--- Synchronet 3.22a-Linux NewsLink 1.2