Update: I was able to trigger the prompt for this Windows 10 Upgrade notice on my Windows 7 system by scanning for Windows Updates.
I then captured screenshots and you can now see all the related screens now for this upgrade prompt at Gallery: Windows 10 Upgrade Notice on Windows 7.
Original post continues...
Earlier tonight a Redditor user named p4block started a thread in the Windows Reddit and shared an image of a notice they got on their Windows 8.1 system that encouraged them to upgrade to Windows 10.
In the same thread at least one other user, who was on Windows 7, also reporting getting the same pop up notification which recommended they reserve their copy of Windows 10.
Here is what the upgrade notification looked like:
Via Redditor User p4block
Of course Windows 10 has not been released yet so the download is not available.
According to user p4block the notice had additional images of the Windows 10 OS and also contains a check for your systems software and hardware compatibility.
You might recall back in April there was a lot of noise about an optional update that Microsoft released to Windows 7 and 8.1 users, KB3035583.
When the folks at MYCE took a closer look at this patch they discovered that it could be used for downloading Windows 10 when it comes to market. There was also code in that update that referred to ads/advertising for the Windows 10 upgrade.
It is very likely that these system notifications are a results of that Windows Update because at least one user in the Reddit thread removed KB3035583 and the notice went away.
Have any of you seen this notice on your Windows 7/8.1 installs over the weekend?
H/T to @Fusionfan45 for the tip.