T420s upgrade to Windows 10 (helpful hints)

[Hans Gruber]

After trial and error using a clean boot Windows 10 USB boot disk. I was able to activate windows 10. I have read there were problems with the T420s/x220 upgrading to Windows 10. In my case there was no valid display driver to migrate to windows 10. It was suggested on this forum that I do a clean install of windows 10. The next problem was activating Windows 10 considering it was not successfully migrated to Windows 10. After getting an annoying Windows 10 is ready to install shortcut on my desktop with many messages reminding me to update to Win 10.

Once Win 10 is installed it will do all the updates for you but will say that you lack a valid digital signature key. The key from your Windows 7 or Windows 8 key is still the activation key. I didn't think putting in my Win 7 key would work after the July 29th cutoff date. Basically since my Win 7 was migrated even though not successfully installed. It was still verifiable using my Win 7 key.

This post is for those who do not want to waste time on hold with customer care. For those with systems that failed to upgrade to Windows 10. You may want to try the clean install of windows 10. It's best to download an iso image from a Windows 10 machine on the Microsoft windows website. You can use (Rufus) or the Microsoft USB iso image. I used both simply for testing purposes.

The upgrade to Windows 10 still works if you attempted to upgrade to Windows 10 during the free upgrade period.