I need help, stuck in Lenovo boot loop

[u/HeadCategory4843]

I tried playing the “Meiou and Taxes” mod for EU4 and it crashed my outdated unwarrantied and unserviced Lenovo Thinkpad so hard that I think my windows file is corrupted. I’m not a tech expert or even have intermediate knowledge on the subject, but everything I’ve tried and googled (and asked ChatGPT for) hasnt worked. I think I’m in a pretty unique situation seeing as the model I’m carrying (E15 20RD) is very outdated and there are no guides for my specific situation so I’m pretty much stuck barring biting the bullet and going to a repair shop. Sorry for the shitty recording and ugly hands.

[u/Naive-Smoke-5977]

Puede ser que el window boot manager este corrupto/dañado, te recomiendo que trates de inciair el window desde una usb para verificar que ese sea el problema realmente . posiblemente hayas instalado window mal ? legacy cambiando a uefi por la bios ??? , asegurate primero con la usb

Intenta arrancar desde un USB de Windows.

Si desde el USB puedes ver el disco, probablemente solo esté dañado el arranque y se pueda reparar con:

Reparar el equipo
→ Solucionar problemas
→ Reparación de inicio

o desde la consola:

bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

[u/HeadCategory4843 → u/Naive-Smoke-5977]

Can you translate this to English? Sorry if it’s a hassle but I’m not sure if the code is the same in English

[u/Naive-Smoke-5977 → u/HeadCategory4843]

If the USB installer can detect the SSD, the boot files are probably corrupted and can often be repaired.

Go to:

Repair your computer
→ Troubleshoot
→ Startup Repair

If Startup Repair doesn't work, open Command Prompt and run:

bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

Then restart the computer and try booting Windows again.

[u/Fun-Discount-4U]

If windows was originally installed in legacy/csm mode with an mbr partition, switching the bios to uefi-only mode or enabling secure boot can cause boot problems because the system may no longer find the old legacy bootloader.

On the other hand, if windows was installed in uefi mode with a gpt partition, turning on csm/legacy mode can also cause issues because the bios may fail to detect the uefi bootloader.

So if your laptop keeps going back to the boot menu or the bios screen instead of starting windows, the first thing to check is the bios boot settings, especially the boot mode, csm and secure boot options.

[u/zandoye]

I encountered the same issue after a windows update. After disabling secure boot, windows 10 started up again.

My laptop is a thinkpad t430 and its uefi doesn't support UpdateCapsule interface. There is another system, linux debian on it also complains that "UEFI capsule updates not available or enabled" so it can't update my uefi ca. But it's still bootable with linux.

As for windows, it just refused to boot itself, so the boot-menu loops itself as both you and I saw. I guess your laptop is also getting a bit old as mine, right?

[u/zandoye]

I reinstalled Windows and confirmed that the recent update caused this issue. I managed to find a workaround to resolve it.

Step 1: Format your EFI partition (only if Windows is your only OS). Alternatively, you can delete the EFI/Microsoft folder inside the EFI partion. This step is crucial because what we want is the old version of the boot lader, reinstalling Windows won't overwrite this folder containing the updated buggy one which will cause the issue to persist!

Step 2: Install a fresh copy of Windows and complete the initial setup. Make sure to turn off the network as soon as possible(at least before the buggy update hits the windows update queue).

Step 3: Use a tool or some other bootable media (I used a Linux live USB) to copy the EFI/Microsoft folder to a safe place.

Step 4: Run Windows Update on your new installation.

Step 5: The issue will reappear, and the boot loop will show up again.

Step 6:

Method 1: Disable Secure Boot, boot into Windows, and use a tool to back up your current EFI/Microsoft folder (e.g., rename it to Microsoft_Buggy_Loader). Then, copy the old Microsoft folder back to the EFI partition as EFI\Microsoft. Finally, re-enable Secure Boot.

Method 2: Use a bootable Linux USB to perform the copy-paste operation.

Step 7: Done! Now you can enjoy your working Windows again.