If you currently have Windows 10 Home installed, you should not have to start a fresh install.
This helped me update from my existing Home install to Pro: Unable to upgrade your edition - Upgrade Windows 10 Home to Pro Fixed - YouTube
Thanks for your detailed replies.
Probably understand where I go wrong. I do a fresh install of Win 10 downloaded from Windows site but unsure which version I downloaded. From your replies, it then take the key from the BIOS to, possibly revert back to Win Home (Original Key). I do not have a pop window to input the new key ( Old days used to have a pop window). I then try to input the new Win 10 Pro (Genuine). I have no error message at all.
If you clean install Windows it will always install the version the OEM key is for, in this case Home. I had upgraded to Pro & after a clean install found myself back with Home so I now use the ei.cfg file which works.
Run the following commands from an admin powershell and copy/paste the output into a reply if still unresolved:
Code:cscript.exe c:\Windows\system32\slmgr.vbs /dli
A Win 10 installation drive (like the one you created using MCT) has many versions on it.
1- Windows 10 Home
2- Windows 10 Home N
3- Windows 10 Home Single Language
4- Windows 10 Education
5- Windows 10 Education N
6- Windows 10 Pro
7- Windows 10 Pro N
If the computer doesn't have any instructions on BIOS it will ask if you want to install Win 10 home or Pro.
As your computer BIOS says it came with Win 10 Home it did install Home. Once installed all you have to do is to change the key and insert the Pro key you bought. It will reboot and upgrade to Pro.
Quote