System Center Essentials finally installed.

I finally managed to get the System Center Essentials VHD working on my windows2008 server this evening. I tried to install it two nights ago but after the installation process got to the Reporting services, it would then remove everything again. Looking through the log files (%temp%\scesetup0.log) I found the error "current security context is not associated with an active directory domain or forest" which didn't help one iota. The server was part of the domain, I was successfully logged in and therefore this shouldn't have been a problem. There was very little information about this in google searches, most of them pointing to .net programming issues.
Trying to reinstall the software would give me different results - one time telling me that I needed to install the xml6 software and another time telling me that the installation had completed successfully but the log files disagreed!
In the end I deleted the vhd file, extracted it again and did the following.
Created a new machine in Hyper-V. Pointing to the extracted vhd, 1gb memory, nic on the external network, everything else was defaults (apart from the file locations).
Start the virtual machine. Log in and remove the virtual machine additions. Reboot.
Cancel the new hardware has been detected, approve the new Hal detection, reboot.
Log in, install Integration services, reboot.
Run Windows Updates (until no more updates found) and update everything (apart from remote desktop 6 client, silverlight) reboot. Make sure that all the service packs for the .net frameworks are installed.
Change the ip address of the dns server to be my existing domain controller, join the domain, reboot.
Take a snapshot of the virtual machine so I can roll back if required.
Run setup program, wait, wait and wait some more - success!
I'm prettty sure that the issue was due to not updating the .net frameworks and then trying to install the software. The first installation left remnants behind that then confused subsequent installation attempts.
Update Now I find that there is a System Center Essentials 2007 sp1 eval software that would probably have been better (although this is just SCE not a vhd). There is also a upgrade to SSCsp1 but I think this only works on retail or licenced versions - not eval ones (I'll find out tomorrow as it's too late to start on this now).
Update2 The upgrade to SSCsp1 does work and is a smaller download.