Voeg -passthroughAuth -s vchostname toe aan de Target regel.
Deze informatie komt van: http://www.vinternals.com/2008/02/virtualcenter-25-passthrough.html
At last! VMware have finally added passthrough auth support in VC 2.5, although it is currently classed as experimental. This is something I have been waiting / asking about for quite some time. And even better, it’s on by default! To use it, simply add -passthroughAuth -s vchostname to the end of the shortcut used to launch the VI 2.5 client.
By default it uses the Negotiate SSPI provider, however since they have fully implemented the interface you can change that behaviour to use Kerberos by adding the following within the <vpxd> node in the vpxd.cfg file on the VC server:
<sspiProtocol>Kerberos</sspiProtocol>
Daarna zie je het volgende scherm als je de VI client opstart:
ICT-Freak.nl 
Thanks Arne! Ik had deze post maand geleden gezien en vandaag toegepast. Mijn VI server staat in een werkgroep en met runas op de client met de local administrator account naar VI gaat prima.