Windows 10: Turn a windows 8.1 laptop running pirated windows 10 to leagal version of windows 10

So I have recently updated my windows 8.1 laptop to a windows 10 but while using the media creation tool it asked me for a product key I did not have a license of windows 10 or a product key so I googled one and I used it to download windows 10 I did not understand why it was not activated and then my friend had told me I accidentally downloaded a pirated version now so does have an legitimate product key which I can replace or a way to turn It legitimate

:)

 

Windows 10

no, you can't go back..
I suggest creating a backup image of your os drive

 

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.

 

Which windows 10 version to choose

I'm making an USB windows 10 installation for my old windows 7 laptop.
Which version of windows 10 to use? I have windows 7 home premium on it.

Should I use "windows 10" or "windows 10 Home Single Language" or "windows 10 N"

Thanks!