In Windows, environment variables have a name and value. All kinds of programs use environment variables to answer questions like: What’s the name of the computer where I’m installed? What is the name of the user account that is running me? What is my current working directory? Where is Windows installed? Where are the temporary files stored on this computer? Where is the OneDrive folder for this user account? So what is an environment variable? Environment variables are, in short, variables that describe the environment in which apps and programs run. What are environment variables in Windows?