[setting up a server (launch.batch) file problem]

I've been trying to start a tekkit server, but when I try to open the batch file it says:

C:/Users/clarson/Desktop/Tekkit Server>java -Xms3G Xmx3G -jar Tekkit.jar nogui

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

operable program or batch file.

C:/Users/clarson/Desktop/Tekkit Server>pause

Press any key to continue . . .

So I press any key ; and then the batch file instantly closes,

what do i do i need help

[My Tekkit crashes immediately when i enter a multiplier server]

It works in single player just fin but when i enter a server it crashes this just started today after i updated the launcher. and it hasn't worked since.

help me some one.