I wanted to install .NET framwork 2.0 on some computer, But the following error occured during setup:

Patch package could not be opened. Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer patch package.


solution:

Use the Windows Installer CleanUp Utility to uninstall .Net Framework 2.0:

http://support.microsoft.com/kb/290301/