Hi there,

In my laptop purchase it had Windows 10 Home installed but the key wasn't shared. 

Questions:

1. If OS corrupts at any point, what should I do?

2. If I upgrade to Windows 10 Pro and then if I revert back to Windows 10 Home, do I need to ask tech support for key?

3. Did Dell installed Windows 10 Home OEM? If yes, If I format the laptop what should I do?