Arduino Uno problem

Hi

I would like to know how can I know if my Arduino UNO ATmega328 is working properly because I can't upload a code on it?
When I plug it on a computer I see the light of the ON led and the L led always ON, and If I press the reset button nothing happens, all the leds stay the same. I would like to know if that means that my Arduino has a problem ?

Thank you