WSUS without Win Server 03/08?

[Switch`]

Right. I want to run Windows Software Update Service (used to just be SUS) on a Windows 7 machine.
Windows 7 Ultimate comes with IIS as an option, and as WSUS is part of IIS
Is it possible to shoe horn WSUS into it?

It was on Win XP with SUS, but I've got no idea about 7 and WSUS

Any idea's?

 

[SiriusB]

I haven't found anything that suggests it's possible.