Reinstalling of OS

[yoshi234]

If i were to change my msi h87-g43 board,intel core i7 4790 to asus z370 and intel core i5 8400. Do i have to reinstall windows?

 

[Colif]

Yes, it would be advisable. Drivers won't match if you just swap the install over. It might work fine but being prepared for errors.

Before doing anything, go to settings/update & security/Activation and see what it says next to activation.

If it says "Windows is activated with a digital license" then the licence is still tied to your motherboard. YOu can link it to an email address by clicking Add an account on the same page

In Windows 10 (Version 1607 or later), you can link your Microsoft account to the Windows 10 digital license on your device. This can help you reactivate Windows using the Activation troubleshooter if you make a significant hardware change later. But you must link the account to your PC prior to the significant hardware change occurring.

It's easy to create a free account with your email address or phone number at account.microsoft.com. Your Microsoft account gives you access to apps and games from Microsoft Store, and lets you see your settings and other stuff across multiple Windows 10 devices..

If it says "Windows is activated with a digital license linked to your Microsoft account" then your licence is already tied to your email address

As such, on new hardware follow this - https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change