This previous forum post from Grif will probably answer most of your questions. This is referring to the leftovers from the SP2 install which, unless I'm mistaken is what you are referring to. Hope this helps.
When I look in c:\Windows I see many folders with a name that starts $NtUninstall. I'm assuming these are Windows updates (first question: am I correct?). If the update has been successfully installed and I have no wish to uninstall it, can I safely delete these folders? I would clear up a bit of disk space if I can. Thanks in advance for answers.