If it's a desktop PC make sure the voltage is compatible. What mains voltage do you have? There may be a red switch on your PSU to swap between 2540/110. Some PSUs are able to handle a wide range of input voltages. It should state what Input Voltage it can use.You may have to get another PSU
Same applies if it's a laptop, you may have to get a new AC adapter.
Otherwise I'm sure there will be a 3 pin to 2 pin adapter for plugging it in.
Take it you're buying a laptop? Then all you would need is the mains lead for the adapter...there are two types, 2 and 3 pins, make sure you get the right one. If it's a PC your old mains lead would be fine.