Symptoms
Windows agent is not starting with:
Error 1314 A required privilege is not held by the client
Despite correctly deactivating UAC the error message persists.
Cause
In Windows 2008 it was possible to deactivate the UAC by setting the User Account Control Settings to Never Notify.
The GUI still exists in Windows 2012, but setting it to Never Notify no longer disables the UAC.
Resolution
A registry change is require.
Set the DWORD "EnableLUA" from 1 to 0 in
"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system".
This requires a reboot, after the reboot the UAC is disabled.