Upgrading to Windows 10 shall be revertible to previous Windows during a period of 30 days. But some users are facing a bit problem: There seems not option in Windows 10 to rollback to the previous Windows.
To cut a long story short, free upgrade from Windows 7 SP1 and Windows 8.1 to Windows 10 ends at July 29, 2016. Therefore I decided a few days ago to upgrade a Windows 7 SP1 desktop machine and a Windows 8.1 convertible to Windows 10. My plan was to activate Windows 10 and revert to the previous Windows version afterward – my intention is, to use Windows 7 SP1 for my production machine till January 2020 – and the Windows 8.1 convertible till the OS support ends (I still have enough Windows 10 test machines).
But those upgrades ended in disasters. The Windows 7 machine shows all desktop shortcuts with a lock, after downgrading from Windows 10. So I was forced to restore a system backup to go back to the old system.
And the convertible, that has been upgraded from Windows 8.1 to Windows 10, suffers from a lack of free space. During upgrade I was running in low disk space and was forced to name a 2nd drive, where copies of the OS files has to be temporary stored.
No rollback option after upgrade from Windows 8.1?
After login I tried to invoke the rollback features provided in Windows 10. After invoking the Settings app via start menu, I navigated to Update & Security – Recovery. But to my surprise, there has been no option to rollback offered.
(Options after logging in as a normal user)
First I thought, it has something to do with the missing space during upgrade. But then I got an idea – I was logged in on a standard user account. So I logged off and logged in with an Administrator account on that machine.
(Options after logging in as an administrator)
After invoking the Settings app and navigating to Update & Security – Recovery, I was able to see the options shown above. Then I was able to click Get started under Go Back to Windows 8.1.
This behavior isn't documented, as far as I know, but it can be explained. The Settings app is a modern UI app, that doesn't support user account control (UAC). Rollback requires administrative privileges. While the old control panel lists all commands, and some with the UAC logo, the Settings app won't show commands not available for standard users. Pretty silly, isn't it.
The further steps to proceed are discussed at Microsoft Answers forum in this Wiki post. But I failed again to revert to the previous Windows, because Windows 10 reported that I need an extra 4 GB free space on my 64 GB SSD. So after all I was forced to use a Windows 8.1 image backup I've created before upgrading to Windows 10.
