Windows 10: How to move my window 10 license to my new compter?

I bought a new computer and I want to move my window 10 license to my new one...


But I lost my license key.


I already registered my old compter to my microsoft ID.


How can I unregister my old PC and register my new PC?


My window 10 is FPP so I can use it again... But I don't know how


Plz help me ..

:)

 

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.

 

Windows 10 upgrade license

The interesting question is that: the upgrade takes place before 29 of July. If I upgrade the PC (change the MB), and I transfer the Win 8.1 license to this new PC (cause 8.1 is retail FPP), will I be able to upgrade to Windows 10 for free? Or a upgrade license must be bought?

 

Windows 10 upgrade license

Hello guys,

I have 1 license of WIndows 8.1 FPP/retail license. I want to upgrade to WIndows 10, but I one thing is unclear to me.
If I upgrade, will WIndows 10 license be retail or it will "turn" into some sort of OEM license?

I ask this because I upgrade my PC, you know, more memory, replace HDD, and I intend to upgrade the MB and CPU to Kaby Lake platform sometime in the future, (and of course sell the replaced hardware)
This thing is not clearly mentioned anywhere.

Thank you.