I got a bit confused by all the different SQL Server 2008 Express downloads that exist, so spend a little time in getting some insight. If you want to download SQL Server 2008 Express you have the following options:
|Microsoft® SQL Server® 2008 Express Edition Service Pack 1||Download|
|Microsoft® SQL Server® 2008 Express with Tools||Download|
|Microsoft® SQL Server® 2008 Express with Advanced Services||Download|
Then I recommend reading the following blog posts. What’s up with SQL Server 2008 Express editions provides an overview of the supported feature of each distribution. The SQL Express 2008 family is getting bigger gives a good insight what the different installation packages do contain.