Microsoft Net Frame Work

This version of the .NET Framework runs side-by-side with the .NET Framework 3.5 SP1 and earlier versions, but it performs an in-place update for the .NET Framework 4, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1 and 4.7.2.

Microsoft Net Frame Work

When you target a particular version of .NET Framework, by default your application is built by using the reference assemblies that are included with that version's developer pack. In scenarios where the matching developer pack cannot be installed on the computer, you can alternatively build against reference assemblies distributed via a NuGet package.

SDK-style projects include this reference by default. For typical .NET Framework projects that were created with Visual Studio, the reference can be added with the NuGet Package Manager UI in Visual Studio. The package contains reference assemblies for many versions of .NET Framework. The version to be actually used is determined by the TargetFrameworkVersion or TargetFramework (TargetFrameworks) property, as already defined in the project file.

Using reference assemblies makes it possible to build projects that target unsupported versions of .NET Framework from the command line. However, you still can't load these projects in newer versions of Visual Studio. To continue building these apps in Visual Studio, the only workaround is to use an older version of Visual Studio.

You may see the following configuration dialog if you try to run an app that requires .NET Framework 3.5. Choose Install this feature to enable .NET Framework 3.5. This option requires an Internet connection.

The .NET Framework is created by Microsoft and provides an environment for running applications. There are different versions available. Many companies develop their apps to run using the .NET Framework, and these apps target a specific version. If you see this pop-up, you're trying to run an application that requires .NET Framework version 3.5, but that version is not installed on your system.

If you still can't resolve your installation issue or you don't have an Internet connection, you can try installing it using your Windows installation media. For more information, see Deploy .NET Framework 3.5 by using Deployment Image Servicing and Management (DISM). If you're using Windows 7, Windows 8.1, the latest release Windows 10, or Windows 11, but you don't have the installation media, create an up-to-date installation media here: Create installation media for Windows. Additional information about Windows 11 and Windows 10 Features on Demand: Features on Demand.

If you're not relying on Windows Update as the source for installing .NET Framework 3.5, you must ensure to strictly use sources from the same corresponding Windows operating system version. Using sources from a different Windows operating system version will either install a mismatched version of .NET Framework 3.5 or cause the installation to fail, leaving the system in an unsupported and unserviceable state.

The .NET Framework is required to run many applications on Windows. The instructions in this article should help you install the .NET Framework versions that you need. The .NET Framework 4.8 is the latest available version.

4.x versions of the .NET Framework can be used to run applications built for the .NET Framework 4.0 through that version. For example, .NET Framework 4.7 can be used to run applications built for the .NET Framework 4.0 through 4.7. The latest version (the .NET Framework 4.8) can be used to run applications built with all versions of the .NET Framework starting with 4.0.

Users can install and run multiple versions of .NET Framework on their computers. When you develop or deploy your app, you might need to know which .NET Framework versions are installed on the user's computer. The registry contains a list of the versions of .NET Framework installed on the computer.

A set of assemblies, which are collections of types and resources that provide the functionality for your apps. .NET Framework and the assemblies share the same version number. For example, .NET Framework versions include 4.5, 4.6.1, and 4.7.2.

The common language runtime (CLR), which manages and executes your app's code. A single CLR version typically supports multiple .NET Framework versions. For example, CLR version 4.0.30319.xxxxx where xxxxx is less than 42000, supports .NET Framework versions 4 through 4.5.2. CLR version greater than or equal to 4.0.30319.42000 supports .NET Framework versions starting with .NET Framework 4.6.

You can use the RuntimeInformation.FrameworkDescription property to query for which .NET implementation and version your app is running on. If the app is running on .NET Framework, the output will be similar to:

The version of .NET Framework (4.5 and later) installed on a machine is listed in the registry at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full. If the Full subkey is missing, then .NET Framework 4.5 or above isn't installed.

To determine whether a minimum version of .NET Framework is present, check for a Release REG_DWORD value that's greater than or equal to the corresponding value listed in the following table. For example, if your application runs under .NET Framework 4.8 or a later version, test for a Release REG_DWORD value that's greater than or equal to 528040.

In the Registry Editor, open the following subkey: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full. If the Full subkey isn't present, then you don't have .NET Framework 4.5 or later installed.

Check for a REG_DWORD entry named Release. If it exists, then you have .NET Framework 4.5 or later installed. Its value corresponds to a particular version of .NET Framework. In the following figure, for example, the value of the Release entry is 528040, which is the release key for .NET Framework 4.8.

The following examples check the value of the Release entry to determine whether .NET Framework 4.6.2 or later is installed. This code returns True if it's installed and False otherwise.

If the app you're running is 32-bit and running in 64-bit Windows, the registry paths will be different than previously listed. The 64-bit registry is available in the HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ subkey. For example, the registry subkey for .NET Framework 4.5 is HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\NET Framework Setup\NDP\v4\Full.

Check the Release REG_DWORD value to determine the installed version. To be forward-compatible, check for a value greater than or equal to the value listed in the .NET Framework version table.

Each version of .NET Framework from 1.1 to 4.0 is listed as a subkey at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP. The following table lists the path to each .NET Framework version. For most versions, there's an Install REG_DWORD value of 1 to indicate this version is installed. In these subkeys, there's also a Version REG_SZ value that contains a version string.

If the app you're running is 32-bit and running in 64-bit Windows, the registry paths will be different than previously listed. The 64-bit registry is available in the HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ subkey. For example, the registry subkey for .NET Framework 3.5 is HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\NET Framework Setup\NDP\v3.5.

For .NET Framework 4.5 and later versions, don't use the Environment.Version property to detect the version of the CLR. Instead, query the registry as described in Detect .NET Framework 4.5 and later versions.

For .NET Framework versions 4, 4.5, 4.5.1, and 4.5.2, the string representation of the returned Version object has the form 4.0.30319.xxxxx, where xxxxx is less than 42000. For .NET Framework 4.6 and later versions, it has the form 4.0.30319.42000.

The .NET Framework (pronounced as "dot net") is a proprietary software framework developed by Microsoft that runs primarily on Microsoft Windows. It was the predominant implementation of the Common Language Infrastructure (CLI) until being superseded by the cross-platform .NET project. It includes a large class library called 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.

FCL provides the user interface, data access, database connectivity, cryptography, web application development, numeric algorithms, and network communications. Programmers produce software by combining their source code with .NET Framework and other libraries. The framework is intended to be used by most new applications created for the Windows platform. Microsoft also produces an integrated development environment for .NET software called Visual Studio.

.NET Framework began as proprietary software, although the firm worked to standardize the software stack almost immediately, even before its first release. Despite the standardization efforts, developers, mainly those in the free and open-source software communities, expressed their unease with the selected terms and the prospects of any free and open-source implementation, especially regarding software patents. Since then, Microsoft has changed .NET development to more closely follow a contemporary model of a community-developed software project, including issuing an update to its patent promising to address the concerns.[2] 041b061a72