Managing Extensions and Updates
You can manage Visual Studio samples, tools, and extensions by using the Extensions and Updates dialog box (Tools / Extensions and Updates, or type Extensions in the Quick Launch window). The dialog box also shows updates for installed samples and extensions. You can also download extensions from websites, or get them from other developers.
You can install extensions from either the Visual Studio Gallery or the Sample Gallery on the Microsoft website. These extensions may be controls, samples, templates, tools, or other components that add functionality to Visual Studio. Visual Studio supports extensions in the VSIX package format, which may include project templates, item templates, toolbox items, Managed Extension Framework (MEF) components, and VSPackages. You can also download and install MSI-based extensions, but the Extensions and Updates dialog box can't enable or disable them. The Visual Studio Gallery contains both VSIX and MSI extensions.
Installing and Uninstalling Extensions
In the Extensions and Updates, find the extension you want to install. (If you know the name or part of the name, you can search in the Search Visual Studio Gallery window.) Click Download, then Install. You must restart Visual Studio in order to load the extension.
If you try to install an extension that has dependencies, the installer verifies whether they're already installed. If they aren't installed, the Extensions and Updates dialog box lists the dependencies that you must install before you can install the extension.
If you want to stop using the extension at any time, you can either disable it or uninstall it. Disabling an extension keeps it installed but unloaded. You can disable only VSIX extensions; extensions that were installed using an MSI can only be uninstalled. Find the extension and click Uninstall or Disable. You must restart Visual Studio in order to unload the extension.
You can uninstall only those extensions that were installed on a per-user basis. You can't uninstall extensions that were installed on a per-machine basis, such as NuGet.
Per-User and Administrative Extensions
Most extensions are per-user extensions, and are installed in the %LocalAppData%\Microsoft\VisualStudio\<Visual Studio version>\Extensions\ folder. A few extensions are administrative extensions, and are installed in the <Visual Studio installation folder>\Common7\IDE\Extensions\ folder.
To protect your system against extensions that contain errors or malicious code, you can restrict all per-user extensions to load only when Visual Studio is run with normal user permissions. This means that per-user extensions are disabled when Visual Studio is run with administrative user permissions. To do this, go to the Extensions and Updates options page (Tools / Options, Environment, Extensions and Updates, or just type Extension in the Quick Launch window). Clear the Load per user extensions when running as administrator box, then restart Visual Studio.
Master Copies and Working Copies
When you install an online sample, the solution is stored in two locations:
A working copy is stored in the location that you specified in the New Project dialog box.
A separate master copy is stored on your computer.
You can use the Extensions and Updates dialog box to perform the following tasks:
List the master copies of samples that you have installed.
Disable or uninstall the master copy of a sample.
Install Sample Packs, which are collections of samples that relate to a technology or feature.
Install individual online samples, which you can also do by using the New Project dialog box.
View update notifications when source code changes are published for installed samples.
Update the master copy of an installed sample when there is an update notification.
Installing Without Using the Extensions and Updates Dialog Box
Extensions that have been packaged in .vsix files may be available in locations other than the Visual Studio Gallery. The Extensions and Updates dialog box can't detect these files, but you can install a .vsix file by choosing it, choosing the Enter key, and then following the instructions. When the extension is installed, you can use the Extensions and Updates dialog box to enable it, disable it, or remove it.
Extension Types Not Supported by the Extensions and Updates Dialog Box
Visual Studio continues to support deployment technologies and the Microsoft Installer (MSI) but not through the Extensions and Updates dialog box by default. The MSI format, which is used extensively for applications, can also be used for extensions. MSI files include complete packages that can be distributed and then installed.
If an MSI-based extension includes an extension.vsixmanifest file, the extension will appear in the Extensions and Updates dialog box.