Hi,
There has been a flood of releases of Betas, RC1s and SP and it is quite natural that we get confused on what to install on what operating system and the requisites.
Windows XP SP2 and Windows Server 2003 SP1 users
Visual Studio 2005 SP1 (Covers the Web Application Project, Web Deployment Project and other issues)
ASP.NET AJAX 1.0 RC ( Provides Microsoft Ajax Library, ASP.NET 2.0 AJAX Controls and optional Control Toolkit, December CTP)
.NET Framework 3.0 (Provides runtime for WPF, WCF, WF & WCS)
Visual Studio 2005 Extensions for .NET Framework 3.0 (Building Workflow Enabled Applications using WF)
Windows Vista Users
Visual Studio 2005 SP1 (Covers the Web Application Project, Web Deployment Project and other issues)
Visual Studio 2005 SP1 Update for Windows Vista (Fixes some of the elevation priveleges issues with Windows Vista)
Follow the steps in Mike's Post for solving the Debugging Issues on Windows Vista
ASP.NET AJAX 1.0 RC ( Provides Microsoft Ajax Library, ASP.NET 2.0 AJAX Controls and optional Control Toolkit, December CTP)
The .NET Framework 3.0 comes shipped along with Windows Vista so doesnt need to be downloaded.
Visual Studio 2005 Extensions for .NET Framework 3.0 (Building Workflow Enabled Applications using WF)
Well, thats an exhaustive list.
The above links are direct download links and in case any of them doesnt work, I would recommend you to visit the following sites for the download link.
Microsoft Visual Developer Center for downloading the Visual Studio SP1 and related stuff.
ASP.NET AJAX Home Page for ASP.NET AJAX downloads.
Microsoft .NET Framework 3.0 Community for .NET Framework 3.0 downloads.
All the above pages have links for respective downlods for the Express Editions also.
Thanks.