As you do not have a games port or a MIDI din plug to connect the MIDI keyboard to the computer, you will have to buy a sound card with a games port or a MIDI to USB interface so you can plug it in via the USB port. Make sure you also have a regular 5pin MIDI lead to connect the keyboard to the MIDI to USB interface.

You will then have to power the keyboard with a 9 volt, 250-300 mA, centre-positive DC power adaptor.