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I am trying to compile a java program I found on the internet and it says that I must check if javac is installed. I installed the JDK a long time ago so it should be working but I get command not found error:

alt text

how can this be resolved?

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up vote 18 down vote accepted

It looks like the javac executable cannot be found because you did not set your PATH environment variable to include it. This is a simple fix.

Since you are clearly using Windows XP...

  • Right click "My Computer" and select "Properties". (or Win + Pause)
  • Go to the "Advanced" Tab
  • Click the "Environment Variables" button near the bottom of the dialog
  • Under "User variables" for your account, there should be a PATH variable, if there is not click "New" and create it with the variable name PATH and the value as the path to your jdk's bin directory (something like C:\Program Files\Java\jdk1.6.0\bin, it is different between installations so you will have to check C:\Program Files\Java for a jdk version). If it already exists but is empty, change it to the path to your jdk's bin directory. If it already exists but is NOT empty, append a semicolon (;) along with the path to your jdk's bin directory.

The value should look like this:

alt text

If there were previous values, it should be separated with a semicolon like so:

alt text

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First check if you still have the java compiler on your computer.

Open a command prompt and type

cd \

dir javac* /s

If it didn't find any files, install the JDK to compile your java program.

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You need to edit the environment variables, as mentioned by John T. The built in windows environment variable editor is kind of a pain, check out Rapid Environment Editor.


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Looks more complicated, but maybe that's just me O_o – John T Jul 25 '09 at 21:47
Have fun editing a paragraph long PATH variable on one line with the built in editor. This editor splits that all up for you into manageable chucks. – James McMahon Jul 25 '09 at 23:41
if you're path variable is that long you're doing something wrong – John T Jul 26 '09 at 4:25
Or just lots of development tools all wanting in on the PATH. – KTC Jul 26 '09 at 4:39

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