Visual Studio 2008 SP1 Beta installation note
Visual Studio 2008 Service Pack 1 Beta released and you can download it here.
But if you previously installed a Visual Studio 2008 Hotfix, you must run the Hotfix Cleanup Utility before installing Visual Studio 2008 SP1 Beta.You can download the Visual Studio 2008 Hotfix Cleanup Utility for Installing Visual Studio 2008 SP1 Beta here.
And if you are using Windows VISTA you should install Service Pack 1 first.