Oh no, I was talking about my old laptop before this dell, which also came with pre installed windows.
So I guess factory reset doesn't automatically install the default one (the original pre installed windows)? Is there any way to actually re-install the original one other than using usb recovery media?
Factory reset goes back to what was shipped from the factory.
If you cannot do a factory reset then the recovery partition is gone.
I don't know what you are asking.