launch.bat wont launch

[dreadnought4629]

i just got the server pack and i chlick on the launch.bat and all it says is

C:\Users\nicholas\Desktop\server>java -Xmx3G -Xms2G -jar Voltz.jar nogui

'java' is not recognized as an internal or external command,

operable program or batch file.

C:\Users\nicholas\Desktop\server>pause

Press any key to continue . . .

and i press a key and the window closes and does nothing more help?