You can install 32-bit and later uninstall and install the 64-bit version.
You can't have both installed at the same time with the same key. Later, if
you do decide on a different version, you will have to use telephone
activation as your key will be 'in use'. Just explain.
"Scali" <> wrote in message
news

5BD420E-7C9C-4864-9723-...
>I have bought the Vista Home Premium upgrade, and have ordered the 64-bit
>DVD.
> Now I was wondering if I am allowed to install only one of them, or if I
> can
> use them both (I think I'll be needing the 32-bit version now and then for
> software that's not compatible with a 64-bit OS, I've had a setup with XP
> Pro
> and XP x64 aswell, for the past few years, but they are different OSes, so
> I
> have two keys).
> Since they're on the same machine, and I can only use one at a time, I
> would
> think that this is within the license terms...
>
> However, is Vista also built this way technically, or can I only use the
> version that I activate first? The next installation saying that the key
> was
> already used, or something?
> I'd like to know before I activate, because if I can use only one, I'd
> like
> to make sure it's the one I want.
> I still have the 32-bit XP Pro installation, so Vista x64 is my preferred
> option.