If Startup Repair fails, the BCD is likely severely corrupted. Rebuilding it manually using is the most powerful fix.
The first step in any repair is accessing the Windows Recovery Environment (WinRE). Since the server cannot boot normally, you must provide external tools to bridge the gap. windows server 2012 r2 boot repair
Need further assistance? Leave a comment below or consult Microsoft’s official documentation on bootrec.exe and DISM . If Startup Repair fails, the BCD is likely