Even an old socket can deliver 10 amperes or 1,200 Watts so the advice looks bad.
My bet is there is something overheating or the power supply is being overtaxed. You could tell more about this PC.
Bought a new gaming pc with power supply 480 watt - ac 120/230 v (50/60Mz). The house I am renting is old and I'm sure has old wiring.The PC will not stay powered on and am told there is a voltage safety switch which is why it is turning off. The tech said to try a voltage converter. Any advise??