.NET Framework uninstaller

The file version is rolled back to the version that was installed by the last service pack when you remove an update for the .NET Framework 1.0, the .NET Framework 1.1, Visual Studio .NET 2002 or Visual Studio .NET 2003

SYMPTOMS
Consider the following scenario. You have a computer that is running the Microsoft .NET Framework 1.0, the .NET Framework 1.1, Microsoft Visual Studio .NET 2002, or Visual Studio .NET 2003. You install multiple updates for the .NET Framework or Visual Studio .NET. You remove an update. In this scenario, the file version of the .NET Framework or Visual Studio .NET is rolled back to the version that was installed by the last service pack.


CAUSE
This issue occurs because updates for the .NET Framework 1.0, for the .NET Framework 1.1, for Visual Studio .NET 2002, and for Visual Studio .NET 2003 were originally designed to work with Microsoft Windows Installer 2.0. The updates were not designed to work with Windows Installer 3.0. Windows Installer 3.0 is not supported on older operating systems, such as Microsoft Windows 95, Windows 98, and Windows Millennium Edition.

Windows Installer 2.0 has a limitation. It does not natively support the ability to remove an update. To work around this limitation, a custom remove functionality is built into the updates for the .NET Framework 1.0, for the .NET Framework 1.1, for Visual Studio .NET 2002, or for Visual Studio .NET 2003.

The custom remove functionality works as follows. The update carries an "anti-patch" in addition to the payload .msp file. When the appropriate command line for the remove functionality is provided to the update wrapper executable program, the wrapper installs the anti-patch. The anti-patch is actually a second update that includes the last known good version of the files in the payload .msp file. This version is the last baseline version, typically from the most recent service pack if one exists. Therefore, when an update for the .NET Framework 1.0, for the .NET Framework 1.1, for Visual Studio .NET 2002, or for Visual Studio .NET 2003 is removed, the file version is not always rolled back to the earlier version. The file version may be rolled back to the version that was installed by the last service pack.

Consider the following scenario. You have two updates for the .NET Framework 1.0 Service Pack 3 (SP3). The first update is the update that is mentioned in Microsoft Knowledge Base article 886906. This update has file version 1.0.3705.6021. The second update is the update that is mentioned in Microsoft Knowledge Base article 928367. This update has file version 1.0.3705.6060.

http://support.microsoft.com/?kbid=938244