I am glad you are giving me the advice I have been doing thus
far.
It seemed to havev limited effect.
1) He is still rude, altho he hasn't been playing computer for 2
weeks.
2) He told me repeatedly that in order for him to stop being rude,
I have to let him play computer daily. To me, This is definitely a
"no, no" until he behaves.
3) Sometimes, we relax when he is nice for that afternoon, so half
an hour computer, then he reverts back to his old behaviour when I
try to correct him on his mistakes. So my hubby n I told him that
his promise (No 2) does not hold. He turned and twisted the matter
that this computer time was given because I rewarded him for
finishing certain chores or meeting certain criteria,, not given
unconditionally (as in No 2).
4) He is often rude when I try to teach him life values. Like
respect for mom and dad, talk gently and politely, treat his
younger brother nicely (no elbowing etc), be respectful and nice to
teacher, don't be class clown.
5) He is popular with his friends, but not teachers. He is an A
student.
I think he is getting too arrogant and thinks he is good. He seldom
takes my advice as he said " What if I take your advice and live to
regret it later?"
I think his father has a worse time with him.
We both are at our wits ends.
At heart, he is good. He is displaying bad behaviour to make me
miserable because I made him miserable (by not letting him play
computer). 
