This is a well tested fix for us to use if we have this error. This will appear if you have not purchased a serial key from microsoft itself. The best thing to really do is to purchase a genuine serial key from a legitimate microsoft dealer to remove the error, may it be windows 7 or previous versions.
This fix will generally remove the microsoft activation required error. But it is strongly recommended that you purchase a genuine key but if it really is too hard to get, then do it on your own risk.
You need to follow instructions for this.
You can try each instructions vice versa, it doesn't matter.
Important: After all instructions are followed, please install license windows to activate the windows account
Have fun! Proven and tested guys so no need to worry!!