I have installed XP and Vista as VMs to use with VDI. I created a template for each OS and deployed images for myself to use. XP is working fine. Ran into and issue with Vista. It is in workgroup mode. When I tried to join it to our domain it prompts me to join the domain but that process then times out. I get a DEP error. This is 32 bit Vista with SP1. Tested with firewall off and verified DNS setting. I can ping the DCs in the domain I'm trying to join. Do not see anything of value in the event logs of the DCs or Vista.
I thought this might be a Vista SP1 issue. I uninstalled VDM agent and was able to join the domain. After I joined the domain I installed the VDM agent again. Not good for template use.
I got exactly the same symptoms and can confirm I resolved this by uninstalling the VDM agent.
I was trying to manually add a Vista VM to a 2003 domain and kept getting the error about SystemPropertiesAdvanced.exe being halted by DEP. Removed the VDM agent and surprise, surprise it's working. The faulting module was wscredf.dll_unloaded
Vista Business with Sp1 VDM agent 2.1.0-596