Hi Ken and Rick,
Thanks for your quick replies and for confirming that you can't use the
licences that way. I thought the language was pretty clear. In fact, I
was only thinking of dual booting because I'm only going to have Vista
installed for the interim period between now and the upgrade arriving
and wanted to have a bit more of a chance to use it. Pretty silly
really.
If you'd excuse a bit of a rant though - I wouldn't agree that the
price of the upgrade has anything to do with the fact that the upgrade
invalidates a licence you have already paid for. I think there are a
number of reasons a software company might not charge full whack for an
upgrade:
1) When someone already has a product that works that they have paid
for in full, they're going to take more convincing that they need to pay
for another version of it that does essentially the same thing (albeit
better / with more features). If you can convince people to pay a
discounted price for the upgrade then you're getting more money from
them than if they don't upgrade at all.
2) If as a software company you know that you are only going to support
old versions for a given period of time, it is to your advantage if
people upgrade - especially if they pay you for the privilege.
3) Customers are more likely to stick with you if they feel that you
are rewarding them for their loyalty. A discount on the full price
gives customers that warm feeling.
4) As is the case before a big new release, if you don't offer free
upgrades then people will just hold of buying until the new version is
available: not great for the cash flow!
However, looking at this the other way, it is obviously in Microsoft's
gift to say to customers, hey you paid for the original version and paid
for the upgrade, so if you aren't going to abuse it by installing
multiple copies of the software on multiple machines, then why not go
ahead and use the old version you paid for if you want to. They just
happen to have chosen not to do that.
Comercially, that might make a difference to them if they think people
would pay extra to buy full versions of each OS to install on the same
machine - but I think that Ken's hit the nail on the head when he says
that there's no point in doing that. It's just sad anoraks like me who
might like to have a bit more of a 'go' on Vista and are prevented from
doing so who think that the Microsoft legal department are kill joys!