You can allow the user to access the VM console if you have configured an End User
Policies -> Virtual/Hypervisor Policies -> Service Delivery -> End User Self-Service Policy -> Add
In this policy scroll down to Launch VM Console and select it.
Please any other interactions you wish the user to have such as the ability to do Power Operations.
Save
Go the vDC for that catalog item and edit it.
In the "End User Self-Service Policy" (at the bottom of the Edit window) select the Policy you created above.
Save it.
Get the user to refresh their page. They may have to log off and back on again. A refresh worked for me under 6.0.
They will then be able to launch which ever type of console window you allow them to use: Web, RDP, VMRC. when you created the catalog item.
this way the user can then take the actions on the VM themselves.
Do not know off the top of my head about the completing the Windows installations part....
HTH anyway