Connect to HDMI if the PC has a DVI or an HDMI-connection.
Note: if you have connected from DVI to HDMI connect an audio connection cable as well to the 'DVI (AUDIO IN)' connection.
If the PC does not have an HDMI or DVI connection but has an S-video OUT connection connect with an S-video cable to S-video at the side of the TV. Connect an audio cable (red and white cinch) to the 'AUDIO IN' side connection.