star rating showing as letter S on 1 pc only

I am using WordPress theme 2012 and the WooCommerce plugin. A friend of mine said he has only letter “S”‘s where the stars should be for the star rating system. On other sites he gets the stars NOT the “S”. He is using google chrome, it is the latest version and the same as my version. My browser displays the stars in chrome and firefox just fine. We both are using Windows. I have searched the forums and implemented any additional CSS I can to try and assure stars will be displayed for the star rating system on his computer. He is still getting “S” in place of the stars. Any ideas why this may be happening. Seems like it is probably a setting on his PC? Is there a way to fix this?