Yes, that is what I meant. I wanted to be sure you had not started the Win 10 Upgrade installing. And good you didn't or hadn't. X out of the Windows Update windows, close it. Next, open start menu & type View Update History, go there & make sure the Windows 10 Upgrade is not showing on the list. Next, go back to the Search box & type in Check for Updates. IF you find the Windows 10 Upgrade listed right click & look for Ignore or Hide and click on that. However, having never started it, closing the update window should get you out of the situation.
Then go back to where you get the Download for the ISO
http://windows.microsoft.com/en-ca/windows/preview & hit the Get Started button. The next page hit Join Now then the next page download the 64-bit or the 32-bit version. You save the download and then, you either burn it to a DVD & use that to dual-boot installing to another drive or partition,
if you have one available OR you create a virtual machine of windows 10 using Microsoft VPC, since I see you are using Windows 7
http://www.microsoft.com/en-us/download/details.aspx?id=3702 7 will direct burn ISOs to DVD. Rt Clk to ISO & select Burn Image. Although, when creating a VM to can just point to the ISO & not need to burn a DVD, @ all.
Since it was not started you should be able to get out of it. Please, let me know it all goes well. The good part is you realised what was about to happen & knew enough not to proceed.
Wiping out your production machine w/ a beta OS is, you're right, certainly, the wrong thing to do, so, kudos to you for that and for, apparently, aborting in time.
Cheers,
Drew
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View attachment 28573