sorry i was in a rush when i posted that and my information and grammar are horrible!
I have a HDTV that i use as my monitor. It's connected to my HD4850 via HDMI cable. Through this i am able to get sound from my tv. every so often there is no sound, so i go into the control panel and check the sound properties. It shows that i have my speakers plugged in (regular headphones that i plug into my speaker jack on the motherboard) and it shows the HDMI device as an option, but it says it's not plugged in. The only way i found to remedy this would be to reset my computer, which i wish i didn't have to . this started happening about 2 days after i overclocked my computer, at the same time i added a heat sink and the side case fan had to be moved lower and is now in front of the video card blowing air in.