If it is installed on your computer you can use Keyfinder to retrieve it.
If it is not installed anywhere then you need to contact MS.

"rde" <rde@discussions.microsoft.com> wrote in message
news:B7842090-B548-4C00-8D69-5D79E7B2E898@microsoft.com...[color=blue]
>I have lost my product key; is there any possibility of recovering it?[/color]