Look athttp://www.microsoft.com/technet/prodtechnol/sql/2005/sqlupgrd.mspx
andhttp://www.microsoft.com/downloads/details.aspx?FamilyID=3d5e96d9-0074-46c4-bd4f-c3eb2abf4b66&DisplayLang=en
With the SQL2005 Standard and Developer installation disks, there is an upgrade advisor package which you should run. This package should be available as a separate download.
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