Force Windows 10 to boot with iGPU only?

[Doctor McNinja]

I believe the dGPU in my laptop has died. Which causes the rather odd problem of my laptop having no qualms about booting any Linux or *BSD distro I throw at it but it will not boot anything Windows based (including 7, 8, 10, and boot disks like Macrium Reflect etc.). At the risk of sounding rude, this issue of a seemingly dead dGPU is over a year old at this point. I've tried so many different fixes that it's unlikely that any suggestion you might have, will be new to me or something I haven't already tried. I do appreciate people wanting to help but I would ask that you focus on the question at had please.

So back to my question....

My working theory is that during boot, Windows tries to access / start the dGPU but when it fails to address the dGPU, the boot process fails. For what ever reason, Linux and BSD based OSs and boot discs don't have the same issue. Which makes me wonder whether it'd be possible to boot Windows in such a way as to make it not access the dGPU at all? The caveat though, is it can't be a software solution that would first require booting into Windows... unless it could be done on another, differently specced machine or in a VM.

Is there a way to force Windows 10 or 11, to boot without ever interacting with the dGPU in my laptop?

 

[Murphy]

Sounds more like something that would be done in the BIOS but without knowing what laptop it is, how far it gets when the Windows boot process fails, what the failure is, or even if you can force it into safe mode it's kind of difficult to know what to suggest.

 

[Doctor McNinja]

Sounds more like something that would be done in the BIOS but without knowing what laptop it is, how far it gets when the Windows boot process fails, what the failure is, or even if you can force it into safe mode it's kind of difficult to know what to suggest.

The laptop is a Lenovo T480 with an Nvidia MX150. As I mentioned, I've tried a huge list of possible fixes, which includes all manner of BIOS settings changes, and combinations of settings, as well as factory default restores. I've reflashed, upgraded, and downgraded the BIOS, not to mention updating other firmware. As I said though, this is not a new issue and I've already tried a huge list of troubleshooting ideas. Which is why I would like to focus on the question of booting Windows without it accessing the dGPU.

With Windows 10, the boot process fails at the spinning dots loading screen. The dots will spin for a few seconds before freezing for a few more seconds. Then the laptop powercycles. I'm never able to get beyond that, including not being able to get to the Windows boot options / diagnostics menu.

 

[Murphy]

Then the laptop powercycles. I'm never able to get beyond that, including not being able to get to the Windows boot options / diagnostics menu.

Which is kind of wired as after the third failed attempt it should try to boot into the repair environment (this) that lets you choose whether to boot into safe mode, a command prompt, etc, etc. (It's the same environment that boot disks like Macrium Reflect, and Windows setup/install use so is about as basic a version of Windows as you can get to make sure it can load under most circumstances)

If it's not doing that then either the recovery partition doesn't exist (something you can check from Linux) or there's a setting in the BIOS that lets you select what GPU to use and it's set to auto or the dGPU.

Outside of that i don't think there's much you can do if you can't even get it to show the repair environment screen, have you tried booting from a USB with the Windows install media on it? Not to reinstall Windows but just to see if it manages to display the first part of the Windows setup where you get to choose what version to install and where to install it, that would at least rule out if it's a problem Windows has with your hardware or if it's a problem with your particular Windows install.

 

[Doctor McNinja]

If it's not doing that then either the recovery partition doesn't exist (something you can check from Linux) or there's a setting in the BIOS that lets you select what GPU to use and it's set to auto or the dGPU.

Not only does the recovery partition exist, the Windows install in question is bootable when I connect it's disk to another system. Which has lead me to think that it's not the install itself that's the issue.

There is no such setting in the T480's BIOS unfortunately. As for other BIOS settings. I have tried literally every other setting with even the remotest chance of being related to the boot process. If there is a solution to my issue that is related to the BIOS, then the only things I have not yet tried is flashing a very old version of the BIOS, or a custom BIOS (if one even exists).

Outside of that i don't think there's much you can do if you can't even get it to show the repair environment screen, have you tried booting from a USB with the Windows install media on it? Not to reinstall Windows but just to see if it manages to display the first part of the Windows setup where you get to choose what version to install and where to install it, that would at least rule out if it's a problem Windows has with your hardware or if it's a problem with your particular Windows install.

When I said that the T480 will boot any "Linux or *BSD distro I throw at it but it will not boot anything Windows based (including 7, 8, 10, and boot disks like Macrium Reflect etc.)", I was referring to the installation media or bootable ISO, as well as the Win 10 installation media and the existing install.

 

[darael]

Have you explored the possibility of modding the BIOS to potentially gain access to the option that allows you to disable the iGPU? If not, I would start here:

Lenovo T480 Bios Mod

Hello, I hope this is the right area to post. I wo

www.bios-mods.com

 

[Murphy]

...the only things I have not yet tried is flashing a very old version of the BIOS, or a custom BIOS (if one even exists).

Yea, no, if the setting isn't there it's very unlikely that a different BIOS version will have it and I'm hesitant to recommend a custom BIOS because you're very much in buyer be aware territory, it's something i would try but i wouldn't suggest someone else do it because i wouldn’t want to be responsible if something went wrong.

I was referring to the installation media or bootable ISO, as well as the Win 10 installation media and the existing install.

In that case I'm a bit at a loss as the Windows recovery/install environment is about as fail safe as Windows can get, for obvious reasons it's setup to try and start/boot using the simplest of hardware.

I could recommend trying certain things but they'd all be shots in the dark without knowing more about the reason Windows is having issues. If you can boot a Live Linux environment (Linux on a USB drive) it maybe worth checking its boot log to see if/what it's doing anything particular to work around whatever the issue is, that and if Windows has left any logs (.txt) in the Windows folder (maybe ntbtlog.txt).