Microsoft VDI Pooled Workgroup VMs

I'm trying to create pooled workgroup VMs. That means that the VMs that the VDI pool creates wouldn't be domain joined. Is this possible?

Also, does anyone have any working syspreped Windows 7 SP1 answer file? Every time I try, I get an error "vdi unable to retrieve the details of the virtual desktop collection". I have removed the top line shown below as some threads mentioned but I still get the error. I've tried this using the GUI, would doing it through powershell make a difference?