Windows 10: Windows 10 is not activated after latest update

I bought Windows 8.1 Pro and updated my laptop to Windows 10 since 2015. Recently, it started to warn me to activate the windows. I tried to activate and change key using old windows 8.1 key but it doesn't work. Please help !



:)

 

Windows 10 Activation (Insider)

How long did you wait for activation?
When I re-installed with a fresh install... it took a few hours to sync and activate.
However, it did, finally, activate.

 

DOWNLOAD WINDOWS 10 NOW - Upgrade and ISO direct from microsoft

Click to expand... Yeah I went to that site, why do I need to buy a key?
I won't buy a key, stupid.

I'll revert back to windows 7 then.

When I still was on windows 7, about a year ago I added 4GB extra ram which is a total of 8GB now,
is that causing the problem?

 

Microsoft to make Windows 10 updates mandatory

Well, at the moment at least, you can choose to defer upgrades. Under Settings > Windows Updates > Advanced options you need to check the box labeled "Defer upgrades". What does that do? Good question. The answer I've found might illuminate it to a degree.

http://windows.microsoft.com/en-us/windows-10/defer-upgrades-in-windows-10

I hear this only applies to Pro and Enterprise editions. But I can't verify that.