You can check to see if you already have the .NET Framework 1.1 installed by clicking Start on your Windows desktop, selecting Control Panel, and then double-clicking the Add or Remove Programs icon. When that window appears, scroll through the list of applications. If you see Microsoft .NET Framework 1.1 listed, the latest version is already installed and you do not need to install it again.
If you don't have .NET Framework installed on your computer, you can download it for free, clicking here (!! it is important that you choose the same language as your operating system !!)