Team fortress 2 glitch graphics help?

ok firts of i havea Intel Graphics Media Accelerator 3100 GPU but the verticies of my charecter are stretched. its like all of his color has been stretched to the other side of the rooms because when i die im just a black figure no color. i cant play like this. the computer i baught was soppoused to be a home/gaming computer with the specs it has so what can i do to stop this.