Wayne, if Alice needs to join a domain then you need Pro or Ultimate. If she wants to be able to watch DVD's without a hassle and some other multimedia stuff and doesn't need to join a domain then Home Premium is great. If she wants full-drive encryption, all the bells and whistles, and the ability to join a domain and play multimedia easily, then Ultimate. I personally use Home Premium, because I don't need full-drive encryption or the ability to join the domain on my laptop.
