Should I renew my warranty for a three year old notebook computer

My Dell Inspiron computer is about to turn three in two weeks. Is it worth renewing the warranty for another year? So far this machine has not given me any hardware problems. I am a heavy user and I do travel quite a bit.

My friends suggested that I should forego the extended warranty as it is quite expensive. Instead, i should use the computer confidently as it has not had any problems so far. Can someone advice. I am based in Asia.