Azezo - 2011-04-05

OS : win7 64bit
Sound : Reaktek High Definition Audio, Logitech G35 Headset
i got those issue with sound all of sudden:
1- i discovered it when i was in YouTube and all of sudden i can hear any sound from any Video there, i tried to refresh the page the sound worked for 5 sec of the video then disappeared again.
2- so i decided to watch a movie i just downloaded in AVI format the movie started ok for 10 sec then the sound disappeared again, i kept surfing the net for solution while the movie playing in the background and i noticed that the sound sometime comes and disappear as it pleased.
3- i went a head and reinstalled "K-Lite_Codec_Pack_700_Mega + K-Lite_Codec_Pack_64bit_460" to make sure i have the latest codecs but still no sound after those 5 sec.
4- i tried all other media formats "mkv ogg avi mov mp4" "MP3" all of them have the same problem although i didn't have this problem before it seems that my PC just decided i should have a problem today.
5- I went to control panel > sound > Right click in the Default Device > test.    i hear the sound of the test for 5 sec then it disappear again i though the test stopped but it running but no sound.
6- i changed my Default Device sound to TV HDMI but still same thing.

Anyway i can solve this?