Installing the .NET Framework
.NET is an integral part of many applications running on Windows and provides common functionality for those applications to run. For developers, the .NET Framework provides a comprehensive and consistent programming model for building applications that have visually stunning user experiences and seamless and secure communication.
This article provides links for installing the .NET Framework 4.5, its point releases (4.5.1, 4.5.2), and the .NET Framework 4.6 on your computer. If you're a developer, you can also use these links to download and redistribute the .NET Framework with your apps.
Note that installing a new version of the .NET Framework doesn't always replace a previous version. For more information about versions of the .NET Framework and how to determine which versions are installed on a computer, see .NET Framework Versions and Dependencies and How to: Determine Which .NET Framework Versions Are Installed. All of the .NET Framework versions listed in the following table are in-place updates to the .NET Framework 4. In other words, if you install a later version, such as the .NET Framework 4.6, you do not first have to install the previous versions, such as the .NET Framework 4.5, 4.5.1, or 4.5.2. Similarly, if you install a later version, such as the .NET Framework 4.6, you do not first have to uninstall the previous versions, such as the .NET Framework 4.5, 4.5.1, or 4.5.2.
For information on the .NET Framework 3.5, see Installing the .NET Framework 3.5 on Windows 8, Windows 8.1 and Windows 10.
Use the following table for quick links, or read further for details. To view the system requirements for the .NET Framework before installation, see .NET Framework System Requirements.
.NET Framework version
Included in Visual Studio 2015. For more information, see Welcome to Visual Studio 2015.
You can also install on:
For use with Visual Studio 2013, Visual Studio 2012, or other IDEs
You can install on:
For use with Visual Studio 2012 or other IDEs
You can also install on:
Included in Visual Studio 2012
Also available as part of the Windows 8 SDK
You can also install on:
For a general introduction to the .NET Framework for both users and developers, see Getting Started. For information about deploying the .NET Framework with your app, see the deployment guide. To read about the architecture and key features of the .NET Framework, see the overview.
Install a developer targeting pack to develop against the most recent version of the .NET Framework in Visual Studio or another development environment, or download the .NET Framework redistributable for distribution with your app or control.
The developer pack for the .NET Framework 4.5.1 or 4.5.2 and the targeting pack for the .NET Framework 4.6 provides the .NET Framework 4.5.1 or 4.5.2 or the .NET Framework 4.6 reference assemblies, language packs, and IntelliSense files for use in an integrated development environment such as Visual Studio. If you are using Visual Studio, the developer pack or targeting pack also adds the installed version of the .NET Framework to the target choices when you create a new project. Choose one of these developer packs or the targeting pack:
.NET Framework 4.5.2 Developer Pack to install version 4.5.2 on Windows 8.1 or earlier, Visual Studio 2013, Visual Studio 2012, or other IDEs.
.NET Framework 4.5.1 Developer Pack to install version 4.5.1 on Visual Studio 2012 or other IDEs.
From the developer pack download page, choose Download. Next choose Run or Save, and follow the instructions when prompted.
These installers download the .NET Framework components for an app or control that targets those versions of the .NET Framework. These components must be installed on each computer where the app or control runs. Both installers are redistributable, so you can include them in the setup program for your app.
The download page is provided in several languages, but most of the downloads are provided in English only. For additional language support, you must install a language pack.
Two types of redistributable installations are available:
Web installer (web bootstrapper) downloads the required components and the language pack that matches the operating system of the installation computer from the web. This package is much smaller than the offline installer but requires a consistent Internet connection. You can download the stand-alone language packs to install additional language support.
Offline installer (stand-alone redistributable) contains all the required components for installing the .NET Framework but doesn't contain language packs. This download is larger than the web installer. The offline installer doesn't require an Internet connection. After you run the offline installer, you can download the stand-alone language packs to install language support. Use the offline installer if you can't rely on having a consistent Internet connection.
Both web and offline installers are designed for x86-based and x64-based computers (see system requirements), but do not support Itanium-based computers.
To install or download the .NET Framework from the Microsoft Download Center, follow these instructions. You can also use the links in the table to download the .exe files directly.
Open the download page for the .NET Framework version you want to install:
Select the language for the download page. This option does not download the localized resources of the .NET Framework; it only affects the text displayed on the download page.
If prompted, select the download that matches your system architecture, and then choose Next.
When the download prompt appears:
If you want to install the .NET Framework on your computer, choose Run, and then follow the prompts on your screen.
If you want to download the .NET Framework for redistribution, choose Save, and then follow the prompts on your screen.
If you want to download resources for additional languages, follow the instructions in the next section to install one or more language packs.
If you encounter any problems during the installation, see Troubleshooting Blocked .NET Framework Installations and Uninstallations.
The .NET Framework 4.5.1 and 4.5.2, as well as the .NET Framework 4.6, are in-place updates to the .NET Framework 4.5.
The .NET Framework 4.5, its point releases, and the .NET Framework 4.6 replace the .NET Framework 4. When you install these versions on a system that has the .NET Framework 4 installed, the assemblies are replaced.
Uninstalling the .NET Framework 4.5, its point releases, or the .NET Framework 4.6 also removes pre-existing .NET Framework 4 files. If you want to go back to the .NET Framework 4, you must reinstall it and any updates to it. (See Installing the .NET Framework 4.)
You must have administrative credentials to install the .NET Framework 4.5, its point releases, and the .NET Framework 4.6.
The .NET Framework 4.5 redistributable was updated on October 9, 2012 to correct an issue related to an improper timestamp on a digital certificate, which caused the digital signature on files produced and signed by Microsoft to expire prematurely. If you previously installed the .NET Framework 4.5 redistributable package dated August 16, 2012, we recommend that you update your copy with the latest redistributable from the Microsoft Download Center. For more information about this issue, see Microsoft Security Advisory 2749655 and Knowledge Base article 2770445.
Language packs are executable files that contain the localized resources (such as translated error messages and UI text) for supported languages. If you don't install a language pack, .NET Framework error messages and other text are displayed in English. Note that the web installer automatically installs the language pack that matches your operating system, but you can download additional language packs to your computer. The offline installers don’t include any language packs.
The language packs don't contain the .NET Framework components that are required to run an app, so you must run the web or offline installer before you install a language pack. If you have already installed a language pack, uninstall it, install the .NET Framework and then reinstall the language pack.
Open the language pack download page for the .NET Framework version you've installed:
In the language list, choose the language you want to download, and wait a few seconds for the page to reload in that language.
The following table lists the supported languages.
If you're new to the .NET Framework, see the overview for an introduction to key concepts and components.
For new features and improvements in the .NET Framework 4.6, 4.5.2, 4.5.1, and 4.5, see What's New in the .NET Framework.
For detailed information about deploying the .NET Framework with your app, see .NET Framework Deployment Guide for Developers.
For changes that affect the deployment of the .NET Framework with your app, see Reducing System Restarts During .NET Framework 4.5 Installations.
For information about migrating your app from the .NET Framework 4 to the .NET Framework 4.5, see the migration guide.
See the .NET Framework Reference Source to browse through the .NET Framework source code online. The reference source is also available on Github. You can download the reference for offline viewing and step through the sources (including patches and updates) during debugging. For more information, see the blog entry A new look for .NET Reference Source.