I've been messing about in CTF's for a while and I also do pen-testing professionally, what i've noticed is a distinct lack of CTF competitions using windows environments.
This is in stark contrast to the majority of environments I test professionally (that's not to say there isn't *nix used heavily in the environments), just that its (IMHO) way more beneficial to go after the AD infrastructure and the clients rather than exploit a single unix box at a time.
While there's plenty of RE/Binary challenges out there for Windows environments, i'm yet to see a good CTF run which uses Windows networks rather than *nix variants. I might be totally wrong or just playing with lame challenges but I suspect that licensing issues plays a large part.
I feel this is important as when grads and other people keen on getting into info-sec start I often recommend playing with CTF's and doing other challenges/virtual environments. What i haven't been able to recommend is a resource that helps with exploiting Windows environments. Plenty exist for Web-apps for example pen-tester labs has pre-configured ready to go VM's for web-app testing which I find great. I think it'd be awesome if something like that existed for specific attack scenarios on Windows as well.
What I'm asking for is the following:
Are there any CTF competitions that run that include Simulated Windows networks as part of the challenges (not just the usual RE binary challenges)?
Are there any downloadable Windows VM's which come pre-configured (Say AD server and 2x client PC's joined to a domain for example but preferably with different configurations say for example kerberos)?
Aside from licensing issues, is there any technical reason why running Windows CTF's isn't practical? I can imagine running a Windows machine as a Virtual one is simple enough to snapshot and restore if someone playing is a jerk and decides to try and trash the machine.