Basics: What H/W do I need?

[robinsmidsrod]

My guess is that the client machines are either using iSCSI to boot, and that 30GB C drive is actually directly connected to a server via the network. Read this if you want to understand more: http://en.wikipedia.org/wiki/ISCSI

A second alternative is that they are using some kind of specialized WinPE (Preboot Environment) that runs completely in memory that mounts the C drive using CIFS/SMB file sharing (or just runs in memory). That might be why you see reports of outdated software, because the image is replaced each time you boot. It might also be possible that they use some kind of system that resets the state of the C drive on each bootup to avoid tampering by users.

I'm sure other people that have more experience with Windows deployment can give you more examples of how it's done.

The correct WIM image is most likely found by mapping the MAC address of the network card to some remote storage volume.

Question 4 might use a technology called copy-on-write volume storage, but it might also be something completely different.