I have installed Visual Studio Team System 2008 Architecture version: 9.0.30729.1 SP and Microsoft Net Framework 3.5 SP1.
When I'm going to add a new item I can't find ADO.NET Entity Data Model template.
SUMMARY There seem to be multiple causes of this problem as many of the other answers indicate.
You may be looking at the wrong level. An Entity Framework Data Model is something that you add to a project, it is not a separate project type.
Right-click on an existing project Select Add, New Item
And then select ADO.Net Entity Data Model...
Make sure you have VS2008 sp1 (http://www.microsoft.com/downloads/details.aspx?FamilyId=FBEE1648-7106-44A7-9649-6D9F6D58056E&displaylang=en). I had .Net Framework 3.5 SP1 installed but not the VS2008 SP1. ...at least that is what I was doing wrong.