You will have to read the EULA as it varies based on OEM (what you get from
Dell, Gateway, .etc) versus Retail (Amazon, local computer store, .etc).
EULA can be found at:
Only if it is a volume license. I doubt that you have one of those. Not sure
that MS has ever sold volume licenses for any quantity under a hundred, or
so. Would be nice if they sold "five-packs", eh?
(But how many people would be willing to pay $450, or so to buy five copies
of a product license?)
The retail version allows 2 installs to computers used by the same person,
one to a portable. It's for people who own and use 2 computers (usually a
desktop and a laptop), not for 2 computers in one family, used by 2
different people.