NET Framework (pronounced as "dot net") is a software framework developed by Microsoft that runs primarily on Microsoft Windows. It includes a large class library named as Framework Class Library (FCL) and provides language interoperability (each language can use code written in other languages) across several programming languages. Programs written for .NET Framework execute in a software environment (in contrast to a hardware environment) named the Common Language Runtime (CLR). The CLR is an application virtual machine that provides services such as security, memory management, and exception handling. As such, computer code written using .NET Framework is called "managed code". FCL and CLR together constitute the .NET Framework.The Microsoft .NET Framework 4 redistributable package installs the .NET Framework runtime and associated files that are required to run and develop applications to target the .NET Framework 4.
The Microsoft® .NET Framework includes everything you need to run .NET Framework applications, including the Common Language Runtime, the .NET Framework class library, and ASP.NET.
System Requirements
Supported Operating System : Windows 7, Windows 7 Service Pack 1, Windows Server 2003 Service Pack 2, Windows Server 2008, Windows Server 2008 R2, Windows Server 2008 R2 SP1, Windows Vista Service Pack 1, Windows XP Service Pack 3
• Windows XP SP3
• Windows Server 2003 SP2
• Windows Vista SP1 or later
• Windows Server 2008 (not supported on Server Core Role)
• Windows 7
• Windows Server 2008 R2 (not supported on Server Core Role)
• Windows 7 SP1
• Windows Server 2008 R2 SP1
Server Installation Requirements
If you have to perform a server installation, your computer must have the following software in addition to the basic requirements:
• Internet Information Services (IIS) version 6.0 or later. To access the features of ASP.NET, IIS with the latest security updates must be installed before the .NET Framework is installed. ASP.NET is supported only on Windows XP Professional, Windows Server 2003, Windows Server 2008, and Windows Server 2008 R2.
• (Recommended) Microsoft Data Access Components 2.8 or later
Note: Make sure that your computer has the latest Windows service pack and critical updates. To find security updates, visit Windows Update. If you are installing on XP 64 bit or Windows 2003 you might need to install the Windows Imaging Component.
Most users do not have to perform a server installation. If you are unsure whether to perform a server installation, just perform a basic installation.