Answer to the first part of your query from click here:
"If you are a 'Qualified Family Pack User', you may install one copy of the software marked as 'Family Pack' on three computers in your household for use by people who reside there. Those computers are the 'licensed computers' and are subject to these license terms.
You are a Qualified Family Pack User if you obtained an upgrade license to Windows 7 Home Premium in a product labelled 'Family Pack' on the product packaging and media."
I think that also answers the second part of your query, but if you'd like to further clarify it all, I'd suggest posting your queries in the Microsoft forums. This is the relevant subforum to post in click here. You'll need to be registered & be logged in before posting. G