Unable to find nb command in Nios II Command shell (Altera version 14.0 on Win 7)

I am a newbie in using this Altera tool. I have installed Altera 14.0 on Windows 7.

I would like to build a srec from .c file using nb command in Nios II command shell.

Surprisingly I could not able to find nb command to compile this .c file.

Please help me how to compile and build a flash image.

thanks in advance.

regards,

Naveen Kumar