Startup repair issues

I have an Asus Intel Core i5 Windows 8 notebook. I downloaded Windows 10, hated it, and tried to restore Windows 8. I started having issues with it (can't remember the issues), therefore my husband purchased and attempted to install a new solid state drive (Samsung V-nand ssd 850 EVO). That didn't work out so well. So now I have the old drive back in, and can't get past the startup repair.
In STARTUP REPAIR:
When I click "send information about this problem", it says "windows cannot repair this computer automatically."
If I click "view advanced options for system recovery and support", it takes me to system recovery options with a username: Dummy, and I have no clue what the password could possibly be.
If I click "view diagnostic and repair details", it says "a recent driver installation or upgrade may be preventing the system from starting."

Where should I go from here??? Should I take out the old drive and try installing the new one again? Or is it a lost cause?
 
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