How many computers can I install Windows Vista on using one key?

I bought a copy of Windows Vista, but I'm worried that it might not work on more than one computer and require a different key for each system I install it on. What is the maximum number of computers I can safely install Vista on without needing another key?

I have the Home Premium Edition.

How many computers can I install Windows Vista on using one key?norten

You can use it on all your computers.. you just need to call them if the product key wont work so they can change it.. u should give me a product key to lol... but yeah it will work on all your computers, if it wont work u just need to go and call the costumer service thing when ur on the "activate windows" box and provide them with that number located in the middle and they will change it for ya

How many computers can I install Windows Vista on using one key?panda

2 at the most. after that the product key becomes useless.
One, unless you want to break the law and not get any windows updates on the other computers.

Because windows will find out, they have this program they runs in the background, that can tell whether not it is legal and if it isn';t a message will popup saying that your copy is not valid and will not go away until it is valid.

So that means, if you want vista on more then one computer, you will need to buy a copy for each.
I heard that only one copy per pc, if you install it on more then one they will disable the activation keys.
You can only install it on one computer. Actually, you can only activate it on one computer. If it tries to activate on a second computer and finds that that copy has already been activated on a different computer, then Vista will go into reduced functionality mode. This means that it will remove the start menu and desktop icons. All it will do is start up IE and connect to Microsoft, where you can legally purchase a second copy. It will also shut your computer down after an hour of use.

I believe you can purchase multiple license packs for less, but you'd have to check the MS site for details.
Depends on what kind of key you have. If you just have a retail version out of the box, then it is just one (unless you want to not to be able to get updates). But if you were lucky enough to find a site license key then you could load it on as many as you wanted.