>There are different installation files - you need to pick up the correct installation disk if you're installing from DVD or download the correct version if you use MSDN subscription.
I only have one DVD and it is from June 2009. This is SQL Server 2008 SP1. In Previous, it also shows "SQL Server 2008 Enterprise and Standard Editions". So, it is the correct one. I am confused about how to install it and how to be sure it will select Enterprise and 64bits without no limited in time, such as this 180 days warning I just received.