Hi,
When you run the wuauclt /detectnow task, you need to wait for the completion of the detection event.
Typically this could take a couple of minutes, but on a healthy, fully patched system, it may complete in a matter of seconds.
Regards.
Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com