I do not know about USB-to-HDMI converters. But the laptop may have different video output options, such as VGA, DVI, etc. and the TV set may have other video input options along with HDMI.
If the laptop and the TV set have VGA or DVI connectors, then a simple video cable and a simple audio cable may solve the problem. You need the audio cable ( one end with 3.5 mm jack to laptop's headset connector, the other end with either RCA jacks or 3.5 mm jack depending on the TV set ) because VGA and DVI have no audio capability.