Installation/dos prompt

As a complete Java novice reading - 'Java 2 for idiots', I've downloaded JDK 1.5 update 6 for Windows onto my desktop.

When I attempt to enter the command;-

javac TicTacToe.javaat the prompt, I get the message - 'javac' is not recognized as an internal or external command, operable program or batch file.

1. Have I to launch a particular download file?

or

2. Is TicTacToe no longer supported with the latest version and update?

or have I just done something more fundamentaly wrong!!

Thanks in advance

connelsey

[574 byte] By [connelseya] at [2007-10-2 20:22:33]