The .NET Framework 1.1 is a component of the Microsoft Windows® operating system used to build and run Windows-based applications. For developers, the .NET Framework makes it easy to rapidly create powerful software that maximizes performance, scalability, opportunities for integration, reliability, security, and the end-user experience, while minimizing the costs of deployment and management. For more information, visit the .NET Development section of the MSDN® Library.
Applications built for the .NET Framework require that the .NET Framework be installed prior to running. The .NET Framework Redistributable will install the .NET Framework onto your machine.
Generally speaking, your application vendor will alert you if you need to install the .NET Framework to run a particular application or will install it for you as part of the application.
With the number of .NET Framework-applications on the market growing rapidly, we encourage you to install the latest version of the .NET Framework, if you haven't already.