You need a 64 bit processor in order to install the 64 bit version of SQL Server 2005. Ideal for the Largest Organizations and the Most Complex Data Requirements SQL Server 2005 Enterprise Edition scales to the performance levels required to support enterprise online transaction processing (OLTP), highly complex data analysis, data warehousing systems, and Web sites. With comprehensive business intelligence, robust analytics capabilities and high-availability features such as failover clustering and database mirroring, SQL Server Enterprise can handle the most critical enterprise workloads.