Ok, I resurrected my sister's laptop (don't ask, I removed teh battery, replaced it, and then after attempting to turn it on several times, the screen flickered on), and installed Ubuntu on it. So far it's working fine, I'm just trying to get internet, but that shouldn't be a problem anymore...at least I'm off teh LiveCD.
If I want to downgrade to Xubuntu because of the awfulness of the laptop, is there a way to do it without having to uninstall Ubuntu, and then install Xubuntu? Or is that just wishful thinking?