How-To: Environment Variables in Windows

This is a rather basic yet important tutorial dealing with Environment Variables and setting them up. An example of this would be if you had an execution script such as this: “java -classpath .;cutter.jar Cutter” Those of you at SCAD who have had Prof Kesson should recognize this script. When you try to execute this on your home computer nothing will happen if you don’t have your environment variables set up. Even if you try to open up a new command prompt(be it through Run>cmd or start>accessories>Command Prompt) you will get “‘java’ is not recognized as an internal or external command….”. Oh and for the record any time you are setting up a script in one location and bring it to your home setup it is always a good idea to run it through a Command Prompt window the first time. If it fails the window will open momentarily and close without you being able to read what it said.

So, how does one go about setting up environment variables? Well in the first place you need to have the proper thing installed. I will continue to use cutter as an example. I don’t remember off the top of my head if you can use a JRE(Runtime Environment; ie what you get if you download a plugin through say firefox or going to java.com) or you need the JDK(Dev Kit). Either way install whichever will work and keep reading. While I use Windows7 64-bit this translates down to XP(farther below possibly but who still uses anything less than XP???), you will just have slightly different menu layouts. The first thing you get to do is navigate to wherever your Java is installed. For java all your exe’s are stored in the bin folder(this is true for most things that you would have to set up env vars for). You should see something like this:

So for now leave that window open and set it off to the side. Now open up your start menu and right click Computer (or My Computer for older versions) and go to Properties:

You should now see one of these: XP, Vista, or Windows 7. Now navigate to the advanced window(for non-XP just hit the Advanced System Settings button on the sidebar). Somewhere in the window you should see a nice big button that says “Environment Variables,” click it. You should now have the environment variables window open(brand new window.) In the second half you should see a section labeled System Variables, if you scroll down a bit(or it may be right there) you should see a variable that says “Path.” Highlight it and hit the edit button. Now the next part is important, if you happen to delete this you could potentially mess a few things up(but you can just follow the steps again to redo everything, it will just take a while.) Scroll to the farthest right portion of what is already in the variable value box. To add a new path just add a semi-colon to the last one and take that path that you found earlier(scroll up) and paste that in there. Hit ok a couple times and now Cutter(and any other script using java) should work fine!

As always if you have any questions get in contact with me(through whatever channels you can,) and I will do what I can to assist you.