To fix the window-stop-error you have to follow below step:
Change the product key to an MAK.
Open up the Command Prompt
Type slmgr -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx and press Enter
Fix Activate Windows Error 0x8007007b
This is the process involves calling Microsoft for them to activate it for you. To proceed with activation;
First Open the search menu, click on the start button if you are on Windows 7 or press the Windows key + F to access the search menu if you are on windows 8, or 10.
Next, type slui.exe 4 and press enter. A new window will open up. You can also access this window using the Run command.
Press the Windows key + R, and then type slui.exe 4 in the new window.
Then click on OK button, and the phone activation window will open. After that choose your country from the drop-down list and then select the phone activation option.
A new window will open in front of you with a toll-free number that you can call.
You will be asked to provide an installation ID by the caller on the other side. They will then provide you with the activation code.