show Machines that match Primary User only.

I am looking for the filter criteria that will show me machines that match the Primary user account only.

example : I type in username into the filter criteria 'User Name (UG User Account)' This brings back 3 machines, When i click on each machine in the console and look under General the primary account is correct for 2 of them, for the third there is no mention of that user?

Is there a 'ccorect' filter criteria to use ?

Thanks