The creation of the registry keys is (intentionally) the last step. This is so that if mapupdate doesn't finish, it won't corrupt your mapsource install.
Given that you're using just a subset of the IMGs, you probably don't want my TDB and IMG files anyways. You'll likely want to use something like MapSetToolKit to load them in to mapsource. (Haven't played with this much myself, but it doesn't seem too tough...)
If you have trouble, drop me an e-mail and I'll see what I can do.
Dale
No worries, I'll copy all of the IMG files back onto the laptop, run the update to get the registry items then delete the IMG files I don't need to free up my limited HD space. I'm installing this on friends machines as well so I'll just use my main machine to keep up to date from your server then copy the files from there for a speedy install.