1. Update the PATH variable Trying to run the command: “javac Ex1.java” you’ve may encountered the error: “javac is not recognized as internal or external command, operable program or batch file” To resolve this you need to add the path where the file javac.exe is located to the PATH of your system. The PATH is a list of all locations that the system will search by default while trying to locate some application.

2. To set the PATH permanently, add the full path of the jdk1.7.0_ \bin directory to the PATH variable. Typically this full path looks something like C:\Program Files\Java\jdk1.7.0_ \bin. Set the PATH as follows on Microsoft Windows 7 (very similar on other Windows OS): 1. Right Click on “My Computer” > Properties How to set the PATH permanently

3. 2. you’ll get the following window, click on “Advanced system settings”

4. 3. Then you’ll get another window, click on “Environment Variables”

5. 4. Then you’ll get another window, mark the line starting with “Path” and click “Edit…”

6. 4. Add to the Variable value a semicolon (;) at the and of the line and the path to the directory containing the file “javac.exe”. 5. OK > OK…