Try Harder! of course.
Originally Posted by ripon
look man when this happen alot of reasons may be the cause,try again if you face the same problem that means the system is patched and the other way to exploit the system is to find another exploit,donot give up...
As you have already been told your exploit has failed, there are many possible reasons answering the the question "Why did it fail?" so there is really no point in continuing this.
A little advice, try to find out how these exploits work and understand them don't just use random exploits to see if they work.