You can check the Event Log if this is the same case for you, I got there

SQL Hotfix KBxxx(ENU)installation failed.

KBxxx(ENU) installation did not complete.

then

SQL KBxxx(ENU) uninstall failed.

Fatal error during installation.

Happened to me too. Caused by an interrupted hot-fix deployment. Was fixed by

replacing sqlserver.exe with the old one (force the hot-fix to deploy itself,

otherwise refuses) and make sure...