Visual Studio 2008 does not support having both Visual Studio 2008 without a service pack and Visual Studio 2008 with SP1 installed on the same computer. Because certain SQL Server 2008 features install components that are also part of the release version of Visual Studio 2008 SP1, SQL Server 2008 requires Visual Studio 2008 with SP1. If Visual Studio 2008 without a service pack is installed instead, it may not work correctly after you install SQL Server 2008.