Years ago(recently), HP came stock with Realtek audiocards and drivers, and for some odd reason they wouldn't work when trying to play a game, or any type of .exe or flash. A quick fix was getting an old pair of headphones/earphones, and cutting off the end wire, (only having the jack) and plugging it into the back mic slot. It makes it miraculously work for some reason. Temporary fix to a permanent problem though.