.NET Framework 2.0 Service Pack 1

Provides the latest updates to the .NET Framework Microsoft .NET Framework is the programming model of the .NET environment for building, deploying, and running Web-based applications, smart client applications, and XML Web services.
It manages much of the plumbing, enabling developers to focus on writing the business logic code for their applications.
The .NET Framework includes the common language runtime and class libraries.
The Microsoft .NET Framework version 2.0 redistributable package installs the .NET Framework runtime and associated files required to run applications developed to target the .NET Framework 2.0.
The .NET Framework version 2.0 improves scalability and performance of applications with improved caching, application deployment and updating with ClickOnce, support for the broadest array of browsers and devices with ASP.NET 2.0 controls and services.
Important: You cannot install two different language versions of the .NET Framework on the same machine. Attempting to install a second language version of the .NET Framework will cause the following error to appear: "Setup cannot install Microsoft .NET Framework because another version of the product is already installed." If you are targeting a non-English platform or if you wish to view .NET Framework resources in a different language, you must download the appropriate language version of the .NET Framework language pack