In that case, you would have to do a Reinstallation of the correct version of Windows as downgrading editions is not possible. The activation troubleshooter would say something like this:
Here the user has Installed Windows 10 Pro where he has got a license of Windows 10 Home Single Language. Running the Windows 10 activation troubleshooter The activation troubleshooter should tell you what is wrong with your license. If your Windows is not activated after a clean install and you believe you have a genuine license, first of all run the activation troubleshooter. How to install the correct version of Windows
I would be discussing this case in this article. This also applies to when a user sends a PC for repair to a shop where they install either a pirated copy or a different edition of Windows. The case #2 is fairly common, where the user installs a different version of Windows during a clean install(most commonly choosing Windows 10 Home rather than Windows 10 Home Single Language), rather than he has the license for. Some have a pirated copy of Windows(which is either done intentionally or by a PC repair shop), some install a wrong version of Windows during a reinstall, some do a motherboard change hence the PC activation becomes void etc. I, at Microsoft forums usually encounter a large number of cases related to activation-which include a variety of problems.
