Maybe it has a write error? ':f
If you can find yourself a program that formats discs in DOS, (something that boots off a USB, like Darik's Boot and Nuke) then maybe you can pull out the SSD, put in the HDD alone and format it. Or even just have the HDD in the G750 and install a random version of Windows on it, just so it writes something new to the disk. Once it's running, it should work without fail after. That's what I always do anyway. (The formatting part first of course.)
By the way, Darik's Boot and Nuke is a low level formatter, if you're going to use it, do a 'quick' method, so it only does 1 pass. It'll take around 10-20 mins to do ( I think ).
❤