Windows 10: I accidentally removed my old PC from my devices and now I can't activate Windows 10 on my...

I was an idiot and accidentally removed my previous PC from my Microsoft account and now now I can't reactivate windows 10 on my new PC. Any help on how to get my old PC back on my account?

:)

 

Accidentally remove the old activated PC device, and I cannot reactivate Windows anymore??!!

Today, I've changed my PC and try to activate Windows 10 Pro. But then I accidentally remove the old activated PC from my Microsoft account. And when I try to reactivate my new PC, it keep show the message "We can’t find any devices linked to your
Microsoft account that can be used for reactivating the device you’re using right now." but hey!!! I used Windows 10 Pro for years and I thought my account contains the activation key not the unique device. Please help..

My Windows licence is Digital licence

 

Windows 10 Tweaks

Pressing “Windows+Pause Break” (it’s up there next to scroll lock) opens the “System” Window.

Windows 10: In the new version of Windows, Explorer has a section called Quick Access. This includes your frequent folders and recent files. Explorer defaults to opening this page when you open a new window. If you’d rather open the usual This PC, with links to your drives and library folders, follow these steps:

• Open a new Explorer window.
• Click View in the ribbon.
• Click Options.
• Under General, next to “Open File Explorer to:” choose “This PC.”
• Click OK

credit to Lifehacker.

 

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?