My Windows XP SP2 got update notification of Visual Studio 2005 SP1, but it failed to install. And after that, my .NET applications don’t work any more. I uninstalled all my .NET frameworks and visual studio 2005, but I cannot install .NET framework 2.0 anymore. The setup program complains that “Error occurred while initializing fusion. Fusion could not load fusion with LoadLibraryShim()”. This occurs when installing Microsoft.VisualBasic.Vsa.dll. After struggling for several hours, finally I found a cleanup tool to resolve this problem: http://astebner.sts.winisp.net/Tools/dotnetfx_cleanup_tool.zip. Thanks to astebner.