Unusual error on startup

Hello,
My Dad has just attempted to fix his DVD drive, and ended up buying a new one and replacing it. With the new drive in, windows doesn't boot, with the only GUI coming up being the startup repair bit. It fails, as does trying the other options. None of the other options (including system restore and the memory test bit) seem to do anything, nor are they even capable of finding the cause. I suspect my Dad, in his folly, has probably tried to weld it or something to make it stay in place, yet he swears he hasn't done anything besides plug and unplug the drive. We've tried all the above solutions with the drive unplugged, no change. Replacing the old drive does nothing to change it either

Can anyone think of what the problem is, besides my father and his overabundance of "enthusiasm"?

May be incompatible DVD Drive, try your broken DVD drive and see if it fixes the solution.

If the broken DVD drive works on startup, the new DVD drive may be incompatible. Buy a new one.

If the broken DVD drive does not work on startup, do Startup Repair as you mentioned (startup repair requires at least 3 time scan to fully find and fix startup problems.)

Please let me know if you are having problems,

Dean

Sent from my iPad

I have indeed tried it with the old one in, seems to do nothing new. Just tried the startup repair numerous times, and it still didn't seem to have any effect. Even with the DVD unplugged entirely nothing works