You don't have your environment variables set up
xp / windows 7: start > Right click "My computer" > properties > Advanced System Settings > advanced > Environment Variables > Under system variables, click on the variable "path" and click edit below it > Add your java install path
Your java install path is where you... installed it. Example, mine is C:\Program Files\Java\jdk1.7.0_01\bin
Yours might be similar, but it might not. you might have a JRE folder, not a jdk folder (if you don't develop java)
On Vista, right click the run.bat > edit > replace the line that says "java" with your installation path, plus java.exe in quotations
java > "C:\Program Files\Java\jdk1.7.0_01\bin\java.exe"
save it, and run it.
If you can't follow these instructions without success... Uh google it?