Enable Windows Installer in Safe Mode.
reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\MSIServer" /ve /t REG_SZ /d "Service" /f reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\MSIServer" /ve /t REG_SZ /d "Service" /f net start msiserver