That is what is plugged into the socket. But what is on the actual circuit could include many other wall sockets in you home......depending on how the house was wired. When ever the total draw on a circuit is more than it's rated to handle, the breaker will trip to prevent a meltdown.
GhislainG suggests the breaker is faulty and tripping at too low a load, so it should be replaced. BUT it can only be replaced with a breaker of the SAME current rating. A more likely explanation, though, is that the circuit you plug you computer into has many other items plugged in also so that the TOTAL current is now over the limit of a perfectly good breaker. You would have to move some of those loads to other circuits.
Once the circuit breaker trips (which seems rather easy to do), don't reset it right away. Identify another outlet that still is live and use it instead. At the same time, you could identify what no longer works and you'll know what's connected to the same circuit.