How to Add a Folder to The PATH Environment Variable in Windows 10
This is a tutorial on how to add your own folder paths to the PATH Environment Variable of Windows 10. PATH is a well known and important Environment Variable of not just the Windows operating system but also Linux and macOS.
PATH holds a list of folder/directory locations. So, when using the Command Prompt or anything else that uses the PATH Environment Variable, the executable files in any of those directories can be accessed without the need of changing the current working directory to there or specifying the full path to the file. For example, if you have a file named hello.bat located inside D:\Scripts and you added that folder to the PATH Environment Variable, you will be able to run hello or hello.bat on Command Prompt or Powershell without worrying about the location of the file.
If you wish to see a list of all the folders/directories contained in the PATH Environment Variable, run the following command on a Command Prompt window.
echo %PATH%
Note: Not just the PATH variable, but all Windows Environment Variables are case insensitive. Meaning, you can use either echo %PATH% or echo %path%, both will do the same thing. But it's best practice to be consistent and stick to using one way of writing it.
ADD FOLDER TO PATH
First we need to get to the Advanced System Properties of Windows. Do 
+R to launch the Run Dialogue, and type in SystemPropertiesAdvanced. Then press the Enter key or click on the "OK" button.
On the Advanced System Properties Window, click on the "Environment Variables..." button.
On the Environment Variables window that appears (picture below), select the Path variable under the User variables list and click on the "Edit" button.
Note: You might have noticed that there is a Path variable under the System variables list too. What is the difference between User variables and System variables? It's the scope of the variables. System variables will be available to all the user accounts on that Windows machine. While User variables are accessable to that user only. Meaning, user A will not be able to use the environment variables of user B, and vice versa.
On the Edit environment variable window that appeared, click on "Browse..." and navigate to the folder you wish to add to the PATH environment variable. The folder you chose will get added to the list. Then you can click on the "OK" button.
That is all, the folder you chose will be in PATH. You will need to reopen any already open Command Prompt or Powershell windows.
