Hello, I ran into BOOTMGR is missing and it was suggested that I reinstall windows again, I upgraded from windows 8 to 10 so I do not have a cd or usb but I have a laptop with a seperate verison of windows 10. I used the "Create Windows 10 installation media" and transfered it to a USB and my question is will I have to enter a key or something if I use this install of window 10 from my laptop and install it to my desktop?