I have just done an in place upgrade on my Lenovo W520 from Windows 8.1 to Windows 10. Something I had not tried during the beta programme, sticking to running Windows 10 in VMs (mostly on Azure).

I have to say the process was pretty smooth. I only hit one issue, and this was the usual NVidia Optimus problems I saw installing Windows 8 and 8.1.

This is what happened

  1. With Windows 8.1 running mounted the Windows 10 Enterprise ISO

  2. Ran the setup

  3. It did a few checks and eventually asked if I wanted to keep everything – I said yes

  4. It showed a percentage complete gauge

  5. It copied files OK (about 30%)

  6. It said it had found 5% of drivers (32% overall) and stopped – I left it a couple of hours, no disk or network activity

At this point I was a bit worried. But guessed it was the same problem as I had seen on Windows 8.x; the installer needs to access the Intel GPU as well as the NVidia GPU else it gets confused and hangs. A disabled GPU is not an removed GPU.

So I

  1. I rebooted (via the power switch)

  2. Boot into BIOS (press the ThinkVantage button)

  3. Selected the Enable Nvidia Optimus in the graphics options

  4. Saved and rebooted

  5. The PC rolled back the Windows 10 update (very quickly, less than 5 minutes)
    Note: I had expected to be challenged for a Bitlocker code due to the BIOS setting change during the reboot but I wasn’t

  6. With Windows 8.1 running again I re-mounted the Windows 10 Enterprise ISO

  7. Ran the setup again

  8. It did the same few checks and eventually asked if I wanted to keep everything – I said yes again

  9. This time it completed without error, it took around an hour

So now I had an upgraded PC, and everything seemed OK. Including my Biometric login – I was surprised me as this had been a problem to setup in the past.

Only issue was with my external screen, so went back into the BIOS to disable NVidia Optimus again. This time it did prompt me to re-enter the Bitlocker key. Once this was done I could use external screens with no issues as before.

So a smooth upgrade from our standard Windows 8.1 dev machine image, a good stop gap until our IT team build a Windows 10 image in Systems Center.