Ok i fixed it if this hapens to you you need to set the path for java:
If this doesnt work then complain to robocode wiki becaus i copied and pasted
PATH must be set
Note that it is really important that you point at the 'bin' folder, and not just JAVA_HOME. The PATH must be set so your system knows where to locate java.exe, which is used to start the Java VM that Robocode requires.
Set path on Windows
Add the path to your PATH environment variable, e.g. PATH=%PATH%;JAVA_HOME\bin.
1. Find where you installed Java. The default position at: C:\Program Files\Java\jre6\bin
2. Copy all that.
3. Right click on My Computer and select Properties. The System dialogue should have appeared. On Vista, choose "Advanced system settings" in the sidebar. On XP, choose 'Advanced' tab.
4. Now, click on "Environmental Variables" which is a button at the bottom right.
5. Under the category "System variables" which is the lower box, scroll down to "Path" and double click on it.
6. In "Variable value", go to the end of all that text (Remember to put a semicolon down at the end of the original text first or something bad may happen) and paste in the path of your java\bin directory. The one you copied earlier. Then put a semicolon at the end of the java/bin text.
7. Here's what my Path value looks like: "set PATH=%PATH%%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;C:\Program Files\Microsoft SQL Server\90\Tools\binn\;C:\Program Files\ATI Technologies\ATI.ACE\Core-Static;C:\Program Files\Java\jre6\bin;" (The text highlighted in bold is what you may have to put down)