Do not try to boot that drive. Leave it as a second drive and see if RECUVA can retrieve the files.
So my main hard drive is failing/failed. During an update my screen was stuck with the error Unmountable Boot volume then attempted to repair itself before getting stuck on the choose your keyboard layout. So i removed the drive and replaced it with a new one with a clean install of win 10, however when i reconnected the old drive and gave it boot priority i was unable to boot to the desktop. I tried creating a boot disk on my flashdrive but it was unable to do anything. I wanted to transfer my data from the failing drive to the new one but since i cant get it to the desktop i cant do any transferring. I tried booting into safe mode and was just stuck on a black screen. If i get a hard drive dock will i be able to boot from a clean install then once at the desktop plug in the old HDD to the dock and transfer that way? or am i out of luck?
Thanks to anyone who takes the time to read this and or help.