Java error when making server?

[Cap'n_FoxTrot]

Hello! I am trying to set up a small local server for me and a couple friends to play on. HOWEVER I have a large problem, and I have not found a solution that works. When I start the Launch.bat, I get this message.

"C:\Users\User\Desktop\Tekkit_Server_3.1.2>Java -Xmx3g -Xms2G -jar Tekkit.jar nogui

'java' is not recognized as an internal or external command, operable program or batch file.

C:\Users\User\Desktop\Tekkit_Server_3.1.2>pause"

I simply don't know what is causing this. As I have said, I have tried all solutions I could fine, and NONE of them have worked. I have updated my java, re-downloaded EVERYTHING, restarted my computer multiple times, and many other things. Can anyone help?

[Half]

Try using the java executable, if your computer will let you.

[Cap'n_FoxTrot]

Try using the java executable, if your computer will let you.

Thanks, but how do I do that?

[Cap'n_FoxTrot]

I really don't know how.