"Clint" <Clint@discussions.microsoft.com> wrote in message
news:46095A77-F55C-4243-A55A-7B955FC36896@microsoft.com...
>A couple of weeks ago I upgraded my PC to Windows Vista Ultimate.
>Previously
> it was running on an OEM version of Windows XP Professional which came
> with
> my system.
>
> I have just tried to install Windows XP under Virtual PC 2007, however it
> will not accept the product key, which was always valid whenever I had to
> reinstall XP on my PC.
>
> Can anyone help?


If your windows was an OEM version your product key will only match with an
OEM installation disl.

I would guess you are using somebody elses windows CD, which was not an OEM
version.