how to resolve "your windows license will expire soon" on windows 8.1

Recently i got that error on my laptop while finished booting i can't update to windows 10 cause my driver laptop sony vaio still in progress to develop sony vaio info. it's so annoying and i don't know how should i do to solve this error. In searching on google also youtube finally I got step by step to resolve that problem and it works.

Step by step as follow :
1. running task manager on your computer (press and hold "ctrl+alt+del" keyboard sequence)
2. From task manager press on "processes"
3. on tab find "explorer windows" right click and choose "restart"
4. Go to start menu and type "cmd", then right click and "run as administrator"
5. on command prompt menu type "slmgr -rearm" and click "enter"
6. after that you will got information that you are successful to run that command
7. restart your pc to see change on your system

warning : after i tried that i see on the Windows 10 icon located in the lower right side of the system tray and then is not active anymore, and it says you must activate again your windows so you can update to windows 10. (be careful if your license is original)  hiks :'(

source : windows. help (youtube)