My lenovo P400 ideapad, running win 8.1, crapped out a few months ago (registry error and I can't access my HDD) and I recently got a new laptop running win 10. Last time I tried fixing the computer, it got stuck in a disk-checking loop so I set my broken laptop to boot from its UBS port first. This way, the files on the USB break the loop and allow me access to the command-line and all the fancy win 8.1 blue repair/refresh screens that do nothing.
Obviously the screen works just fine, and I want to use it as a secondary monitor for my working computer. However, I tried connecting both laptops with an HDMI cable but when I press ['Win-key' + P] until I reach the 'extend screen' option, nothing happens on the secondary laptop.
I am no computer expert by any means but I'm guessing that I cannot utilize the broken laptop as a secondary monitor either because:
A) I need a fully functioning OS and that these repair screens and the CLI are not enough, or...
B) The HDMI-port on the broken laptop is not working because the HDMI-driver is on the HDD.
Any ideas on how I can use this perfectly good screen as a secondary monitor WITHOUT having to wipe anything (I still want to try salvaging the broken HDD when I have enough free time to kill).