Different programs and processes require different environments to run. On a single machine, Windows needs to make sure that all programs and processes can access the environments they need.
To do this, Windows needs to know the kind of environment every program requires to work. Windows must store this information somewhere for easier retrieval. Environment variables make that possible.
Environment variables are, in short, data storing mechanisms.
Let’s dig a little deeper to see how environment variables work and how you can create, edit, and delete them effectively.
What Are Environment Variables in Windows 10?
Environment variables are dynamic variables that store data related to creating different environments for different programs and processes.
To understand them better, let us take the example of a program that needs to use a built-in Windows tool to run.
For the program to use the tool, the program needs to know the tool's location to access it. The program also needs to find out if it has permission to use the tool or not. Similarly, there are things that a program needs to know before it can use the tool.
So, a program can access all of this information by asking Windows. Windows then looks up environment variables (EVs) for this data and creates an environment in which that program can run.
In other words, EVs store data that is accessible to every program and process running on the system across all users. The data these variables store helps the programs run in the environment they were designed for.
Some of the most important EVs on Windows include PATH, HOMEPATH, and USERNAME. All of these variables contain values that any user and process of the system can access at any time. For instance, the USERNAME environment variable contains the name of the current user. Windows can look up this variable whenever it needs to find out the name of the current user.
How to Set Environment Variables in Windows 10?
First things first, if you want to set system-wide EVs, you need to have administrative privileges. So, if you are not the admin, inform your system administrator and ask for their help.
Now that you have admin privileges:
- Type Advanced system settings in the Start menu search box and select the Best match.
- In the System Properties box, click on Environment Variables to open the Environment Variables panel.
The EVs panel lists two types of variables depending upon your need. If you want to change EVs for the current user only and don’t want the changes to reflect system-wide, you will change User variables.
On the contrary, if you want system-wide changes, you will change System variables.
Let’s say you’ve just installed Java and want to add the java path to the EVs. To do this:
- Click on New under the User/System variables. This will open up the New User Variable box.
- Enter JAVA_HOME in the Variable name field and browse to the directory where you’ve installed Java to populate the path in Variable value.
Pressing OK will add the JAVA_HOME variable to the PATH variable.
How to Edit Environment Variables
To edit different environment variables, select any variable from the list. Then, press Edit. This will open up the Edit environment variable panel. Here you can create, delete, and edit variables.
From the list of variables, select the one that you want to modify and click on Edit. Afterward, you can change the variable value to anything you like.
You can also delete the variables in a similar fashion.
What Is the Windows PATH Variable and How Can I Change it?
In simple terms, the PATH variable is an address book of programs and commands on your computer. Whenever you have a new program on your computer that you want to run from the command line interface, you must specify its address in the PATH variable.
A thing to remember here, not all programs are in the PATH environment variable. Only the programs that are meant to be used from the command line interface appear in the PATH variable. So, programs intended to be used from a Graphical User Interface don’t have their addresses in the PATH variable.
The way the process works involves Windows looking up the address for a certain command. Whenever you issue a command on a command line, Windows first searches the current directory for the command. If the OS can’t find it in the current directory, it looks up the PATH variable to find the address.
To enter an address in the PATH variable, the process is the same as before. Open up the Environment Variable box, select the PATH variable, and click on Edit.
In the Edit box, you can add, remove, and edit directories.
One final thing to remember, the PATH variable is not the same for every user on a system. So different users can list different directories without changing the variable for every user. So, if you want a tool to be available for every user, you have to edit the PATH variable under the System Variables.
Environment Variables in Windows 10 Store Data that Programs Need to Work
Programs need data to work. To make sure that data is available efficiently, Windows stores this data in global variables that all programs can access. These global variables are Environment Variables.
You can add, edit, and remove Environment Variables inside the Advanced System Settings panel.
Furthermore, if you have more than one user on a machine, user Environment Variables will be different for each user. For instance, one user may have listed a command under the PATH variable that won’t be available for other users.
On the other hand, system EVs are available for all users. These variables require admin privileges to edit or delete.
In short, EVs are Windows’ way to store important data. So, be sure you know what you are doing before modifying them.