Problems creating templates for 2008 and Vista in VMM ?

Create the virtual machine ON the Hyper-V box and not deploy a new machine via VMM. Then configure the virtual machine on the Hyper-V box. Remember to set the security to blank password and enable that it can use a blank password in local security policies.
When you have configured and installed applications, boot a last time and then go to the VMM console and create a template from the virtual machine you just created on the Hyper-V box.

I have tested that this works on several installations where I have seen the problem with creating Windows 2008 and Vista template that work in VMM.

I will create a nice guide and post it here later