Be aware of the possible Windows 10 license implications of upgrading hardware in your PC.–PC Pitstop.
Does New Hardware Require a New Win10 License
by Anand Khanse for The Windows Club
How changing Computer Configuration affects Windows 10 license
Plugging in removable devices will not affect your license. You can use as many plug and play devices as you want.
If you change Hard Disk or add a new hard disk, you will have to check whether Windows still shows activated. Though the Microsoft Answer Desk said that changing hard disks will not affect your activation, I recommend checking it out.
To check Windows 10 activation status, open Settings ? Update and Security > Activation. You can see the status of Activation there. If it says Windows 10 is not activated, click on Activate Now. That should fix the issue. If not, you will have to contact the Microsoft Answer Desk to activate on phone.
The hard disk example is applicable to other hardware parts too. However, if you change the Motherboard, it will be considered a new device. In this case, you will not be able to get the Windows 10 activated automatically. You can contact the Microsoft tech support, but it may still be not accepted. You might have to buy a license for activating Windows 10 in case of motherboard change.
In my opinion, the Motherboard ID is associated with your Windows 10 installation and that is why when you make minor hardware changes, your status is not changed. Even for major changes such as adding or replacing Graphics Card, you have the option to activate it by phone (without paying anything) as the device is the same. But if the motherboard is changed, the computer is considered a new device and hence, it will be necessary to buy a license.