Does a SQL Server 2005 licence allow you to switch between 32 and 64 bit platforms (cross platform rights)?
SQL Server 2005 server licences are offered by platform (32 bit, 64 bit, and IA64). While you should choose the platform that matches your current hardware (in order to obtain the appropriate media), SQL Server licences are not platform-specific. For example, if you currently have a 32-bit server and plan to upgrade the hardware to 64 bit in the future, you can buy a 32-bit SKU today, and later switch to 64 bit without having to buy an extra licence. Clickherefor more information.