1) Same as enabling the option in Messenger Plus!: "Force Messenger Plus! to load when computer starts", IIRC (and to know what that exactly does, search the forums )
2) That question is very hard to explain as it is vague and can be caused by many many things. It is even possible that the admin/guest log in has nothing to do with it and that she just has an issue between Windows Messenger and MSN Messenger conflicting with each other.
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