I'm using Windows 2012 R2 with Active Directory.
One of my DC has had hardware failure. I'd like to promote another server as a DC, but reading online it looks like I need the DSRM password to do so. I did not set up the domain controller and can't find the password written down anywhere. When I try to reset the password on the server while logged in as a Domain Admin, I get the error 0xa90. Google hasn't been much of a help, so hoping someone here knows what to do.
I've already removed the dead DC manually from Active Directory, thinking that might be causing the issue.
C:>Ntdsutil
Ntdsutil: set dsrm password
Reset DSRM Administrator Password: reset password on server null
Please type password for DS Restore Mode Administrator Account: ********
Please confirm new password: ********
Setting password failed.
WIN32 Error Code: 0xa90
Error Message: (null)