The setup files for SQL Server look pretty much the same for all editions. If you saved the files somewhere but didn't indicate in your directory name or a readme file which edition they are for, how do you tell the edition? Running setup doesn't necessarily help, the initial setup screens for SQL Server 2005 Enterprise and Standard both show the same EULA that includes "MICROSOFT SQL SERVER 2005 STANDARD AND ENTERPRISE EDITIONS". To see the edition of the setup files, look in the Servers directory of your installation files from the setup CD (there are two high level directories: Servers and Tools). In Servers there is a file called default.htm and when you open it, you will see the edition of your SQL Server setup files.