Speakers and Sound Cards

What are Computer Speakers
External computer speakers connect to the computer sound card into the green sound card socket, this is the same colour for built in sound cards or PCI installed ones.  Driver may need to be installed but more often than not as the sound is passed through that port by default, plug them in and they work unless the operating system is set to mute speaker sound, check for this in the control panel.

What is a Sound Cards
A hardware interface that is either built into a computer's motherboard or inserted into one of the computer's internal expansion slots. Sound cards allow the computer to play digital audio. Many sound cards also provide a MIDI interface. Computer speakers and microphones can be plugged directly into the cards sockets for audio in and out.

PC Speakers do not produce any sound
External speakers often have their own power button, check the speakers are turned on (LED on) and that the volume on the speakers is also at an audible level.  Check that Windows is not set to mute and that Windows sound levels are audible: Start Menu \ Settings \ Control Panel \ Sound and Audio Devices - set as required.