AQT has a window for viewing and updating Environment Variables. This was borne out of frustration with the ridiculously-bad means that Windows supplied for displaying and updating Environment Variables (though this has been improved in Windows 10).
To show your environment variables, from the Database Explorer window, go to Tools > Environment Variables.
There are three sets of environment variables:
You can use the options at the top of the window to select which of these to display.
Some environment variables, in particular PATH environment variables, consistent of multiple items separated by a semi-colon. AQT will split these out over multiple lines - this makes them much easier to view.
Some environment variables, in particular PATH environment variables, can be quite large and the display will not show the full value. To see the full value, double-click a cell. You will be shown the full value in a popup-box.
To do this, click on Show Update Panel.The Update Panel will allow you to update or add an environment variable.