Windows 10 install boot loop after 75%

I tried to update my Windows 8.1 installation on my Thinkpad T61p to Windows 10. It went smoothly until it finished copying the files (75% complete). It is now rebooting in an endless loop (reboot -> Windows logo with spinning circle -> black screen -> Windows logo with spinning circle -> 75% complete message -> reboot) and I don't know what is causing the problem. I have installed the latest BIOS and tried various changes to BIOS settings with no effect. Does the installer write any kind of diagnostic log that would tell me the reason for the reboot loop? Has anyone managed to solve a similar problem?

i have the exact same problem, have you mange to fix it yet?

I couldn't find any way out of the boot loop, so I decided to abandon the failed update from Windows 8.1 to Windows 10. I started again by reinstalling Windows 8 and updating that to Windows 10. The update failed at 75% but not with a boot loop. Instead, it reverted back to Windows 8 with an error message. By searching on the error message, it seemed that the problem might be caused by a down-level NVIDIA display driver, so I installed the latest driver from the NVIDIA site and tried the update again. This time, the update completed successfully.

I tried it with updated BIOS and it worked. I had the same issues as in the thread.

venkey33 said:

I tried it with updated BIOS and it worked. I had the same issues as in the thread.

how did you update BIOS?

simoncn said:

I couldn't find any way out of the boot loop, so I decided to abandon the failed update from Windows 8.1 to Windows 10. I started again by reinstalling Windows 8 and updating that to Windows 10. The update failed at 75% but not with a boot loop. Instead, it reverted back to Windows 8 with an error message. By searching on the error message, it seemed that the problem might be caused by a down-level NVIDIA display driver, so I installed the latest driver from the NVIDIA site and tried the update again. This time, the update completed successfully.

OK thank you, how did you reinstall windows 8?

dc25 said:

OK thank you, how did you reinstall windows 8?

I used my original Windows 8 install disc and license key.

dc25 said:

how did you update BIOS?

Go to manufacturer's driver download page and use your service tag number and download the needed drivers.