Question Windows 7 RE Using my Key on my girlfriends pc?

Aug 15, 2019

Girlfriends computer installed automatic updates-> PC Restarted->Only boots into startup repair where it comes with the error Boot manager failed to find OS Loader.

It Gets a bit weird here. I can get into BIOS. I cannot get into Advanced Boot options (F8). It simply doesnt work. IF i go into boot manager (F5) and then into Advanced options (F8) it just goes back into startup repair (Which fails and then restarts). I have tried F1 F2 F5 F8 F9 F10 F11 F12 DEL TAB. Nothing can get into advanced boot options?

She bought the PC from an independent shop in Australia and we now live in the UK.
-There is no System Restore point.
-There is no system image
-There is no Windows install disc
-The Windows key is OEM and i cannot download The ISO Files ( Get the message saying to contact the manufacturer)
-There is no restore Partition

Question - Can i use my windows 7 key to download the ISO Files onto a USB And boot off that to repair the Windows install on her PC or will it register my Key on her PC and deactivate mine?

Thanks for any help.