What are Environment Variables?

Environment Variables are string variables containing information that an operating system uses to control services and applications.

Environment variables help applications to know what directory to install files in, where to store temporary files, or where to find the user profile information. They set the environment that the operating system and the applications use to run.

There are two types of environment variables:

  • User environment variables (set for each user);
  • System environment variables (set for everyone).
Environment Variables Dialog Box
Environment Variables Dialog Box (Windows Server 2019)

The variable name shown in the picture, TEMP, is one of the environment variables used by Microsoft Windows. It points to where applications and the operating systems should put temporary files. It’s possible to edit this parameter and change it to something else (but not recommended).

You can also add new environment variables. To do so follow the steps:

Create or modify environment variables on Windows

  1. On your desktop, right-click the Computer icon and choose Properties (or choose System in Windows Control Panel)
  2. Choose Advanced system settings
  3. Click Environment Variables (advanced tab)
  4. Click New to create a new environment variable or click Edit to modify an existing environment variable.
  5. After creating or modifying the environment variable, click Apply and then OK to have the change take effect.

The picture shown above refers to the Environment Variables Dialog Box on Windows Server 2019. The graphical user interface for creating and editing environment variables may vary slightly, depending on your version of Windows.


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