My Arduino Uno R3 give me an electric shock upon touching one of it's pins when my legs are on the ground.

The shock is not that trivial since if the Pin is related to some LED The LED lights up which means that this at least 5mA of current or so. And of course is not from it's 5V outputs
 
The Arduino is being powered from USB-2 from my computer and Even the Ground pin gives this shock.
I Guess this has to do with my computer power supply it's a hector 350W With Two pins without an Earth Connection.

If So Is there a way to just get rid of this annoying shocks? 

I am not that expert with electricity But I am not that Beginner either So I think I can Handle It If someone just pointed me to where I can start searching or something.