How to get product key details in SQL Server 2008 R2?

We may use the below script to extract product key details in SQL Server 2008 R2

USE master
GO
EXEC xp_regread 'HKEY_LOCAL_MACHINE','SOFTWARE\Microsoft\Microsoft SQL Server\100\BIDS\Setup','ProductID'
GO

Reference: Zubair Ahmed (http://mssql-tech.blogspot.com/)