I have Windows 7 installed. I had reserved a copy of Windows 10 through the GWX app and when I got the message it was ready for downloading, I started it. Reason being that, whenever I am ready to upgrade from Windows 7 to Windows 10, I wouldn't have to spend time waiting for the download.

But ... at the end of the download, it came up with a question to accept the License Agreement, which I did (not knowing what would happen if I declined). And the Upgrade Windows box came up, asking me to upgrade now or later. Since I don't want to upgrade now I selected later. But that only gives you the option of today, tomorrow or the day after. To give myself some time, I have selected the last possible day and 23:00 (11pm).

Now I have the situation that Windows 10 is about to be installed, this probably happens at the first boot after the selected date and time (or maybe Windows even reboots automatically at the selected time if the computer is powered-on at that point in time).

Trouble is, I didn't have a chance to make a last-minute backup and any backup I now make of the system partition includes the state of Windows 10 being on the brink of install. Suppose I upgrade to Windows 10 and have to go back to Windows 7, at the next reboot it'll probably re-install Windows 10 !

I think it is rather awkward to have an "offer" to reserve a copy of Windows 10 but then being locked-in to installing it within 3 days of Microsoft deciding to push it to your computer.

I have found the registry entry for the scheduled reboot (probably OSUpgradeRebootScheduledTime under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update), so I can probably postpone the upgrade to Windows 10, but Windows Update will no longer offer or install Windows 7 updates since an OS Upgrade is pending. It only offers to reboot the machine (which does nothing until the specified time I guess).

I would like to go back to the situation where Windows 10 upgrade has NOT been downloaded yet (or at least not scheduled to be installed), so I can:

use Windows 7 for a few more months/weeks

get Windows Updates for Windows 7 for a few more months/weeks

decide myself when to upgrade to Windows 10 (when I am convinced it works and have time to fiddle with it for a while)

A last minute resort could be to delete the registry keys I found, but I would like Microsoft to comment on this and a "proper" way to do it, without breaking the system and without forfeiting the chance of a proper upgrade in the future.

One post here from MS suggested turning off automatic updates, but I think that stage is already passed.

Anyone done something that worked for them? Or any official reply from Microsoft?

I do want to upgrade to Windows 10 within the year, but not now!