Before installing Visual Studio 2008 Service Pack 1, you should first uninstall KB944899, a hotfix which improves performance when stepping through source downloaded from a source server.
If KB944899 is not removed prior to Visual Studio 2008 SP1, sometime during the middle of installation an error will occur and the error dialog is displayed as shown below.
One of many improvements made to Visual Studio 2008 Service Pack 1 is that VS 2008 SP1 Beta customers will not need to uninstall SP1 Beta before installing the release of SP1. The same is true for Visual Studio 2008 Express products and .NET 3.5 SP1 –
Visual Studio 2008 Service Pack 1 is comprised of multiple packages, including executables, installer packages, and patches. Compare this with Visual Studio 2005 SP1 which was a single patch wrapped in an executable. A lot of updates were made to both the .NET Framework and VS 2008 –
Microsoft Visual Studio 2008 Service Pack 1 (Beta) has been released to web, along with Microsoft .NET Framework 3.5 Service Pack 1 (Beta). Included as part of .NET 3.5 SP1 are Microsoft .NET Framework 2.0 Service Pack 2 (Beta) and Microsoft .NET Framework 3.0 Service Pack 2 (Beta).
Setup and deployment is a tricky business. Machines can be in many different and often unforeseen states that cause setup to fail. But rarely will setup actually crash, and that is why setup logs are vital to diagnose install, repair, and uninstall problems.