Have a Dell desktop that was running Windows 11. Someone tried to revert to Windows 10. Now it will not even post. Anybody experience something this drastic?

I suspect it tried to do some kind of misguided firmware update in the process.

Not had that problem but I hope you had taken image level backups.

If not... It sounds like a great opportunity to install Linux!

@Demolishun Try removing the mobo button cell for a CMOS reset.

@sariel How do you install Linux on a computer that doesn't even POST?

@sariel If only they had a backup. I am peripheral to the problem. Mostly just curious.

@Fast-Nop Yeah, they are going to try resetting CMOS.

@Fast-Nop Dell actually has a bootable bios toolset that should be able to fix this.

https://linkedin.com/pulse/...

Instructions are for an Inspiron but it should still work.

The Linux dig was mostly because Linux won't fuck up your bios unless you tell it to. This is because Linux wants nothing to do with it, unlike Microsoft.

@sariel They cannot get it to show anything at all on boot. Like just nothing. No logo, not post.

@Demolishun You can also shorten the battery pins on the mobo (battery and PSU plug removed ofc), and leave it sitting for a while. If that doesn't help, you can also try removing some of the RAM bars (or adding one if the machine has only one), then booting up again.

That would force the BIOS to do some recognising from fresh. If that works, you restore the previous RAM config again.

I guess there is no BIOS flashback option that you could try.

@sariel It is not a REAL Linux dig, unless you say "BTW, I run Arch".

@sariel On a Dell desktop?! No way. These things are straight out garbage.

Turns out on another machine that is similar you never see the boot stuff from the machine because the graphics card doesn't support UEFI? I dunno, that is what I am hearing from them. So it is just failing to boot from windows at this point. So they are trying to figure out how to see the machines boot info.

POSTing has nothing to do with the OS. But that downgrade might have crippled the UEFI partition. Might try booting without disk and see whether it POSTs and lets you enter BIOS then...

Found out that machine is 2017 model. It came without video card as it is a workstation. So they put a 2010 video card in it. Then never noticed that they could not see post because of preinstalled windows 10. So the downgraded windows is refusing to boot, and 2010 video card that doesn't support UEFI cannot show anything on screen. UEFI didn't exist until 2013 apparently.

@Demolishun UEFI is fucking stupid and was only imposed on hardware manufacturers because Microsoft said, "do it or we won't sell you OEM licenses anymore."

Fuck Bill Gates, fuck Steve Ballmer, and fuck Satya Nadella.

The only interactions I have had with UEFI are bad ones.

@sariel That was secure boot. UEFI actually came from Intel and is the only thing that made it from the Itanic.