Win7 sound problem

Hello.
I'm having trouble with my sound on pc. Whenever I start any flash video or open internet sometimes, my sound just switches off. Not just on some particular video but every ware. No media players, no flash videos, no games, no even mouse sound clicks are working, its like plugging it self off. But if I close all the internet videos and press play again, the sound is magically coming back. This happens 2 times after I turn on PC, later it works fine.
I tried to update drivers but it seems that there are no drivers on internet for my sound card, yet I never had that trouble before, it started after I reinstalled windows. Now I use Windows 7 Ultimate 32-bit (6.1, 7600)
I took this from DxDiag (dunno how to attach it here) hope it helps. If i can give some additional info about my sound devices, just tell me how to do it.
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Sound Devices
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Description: Speakers (Realtek High Definition Audio)
Default Sound Playback: Yes
Default Voice Playback: Yes
Hardware ID: HDAUDIO\FUNC_01&VEN_10EC&DEV_0660&SUBSYS_1043C603&REV_1000
Manufacturer ID: 1
Product ID: 100
Type: WDM
Driver Name: RtkHDAud.sys
Driver Version: 5.10.0000.5288 (English)
Driver Attributes: Final Retail
WHQL Logo'd: No
Date and Size: 8/24/2006 11:37:50, 4374016 bytes
Other Files:
Driver Provider: Realtek Semiconductor Corp.
HW Accel Level: Basic
Cap Flags: 0xF1F
Min/Max Sample Rate: 100, 200000
Static/Strm HW Mix Bufs: 1, 0
Static/Strm HW 3D Bufs: 0, 0
HW Memory: 0
Voice Management: No
EAX(tm) 2.0 Listen/Src: No, No
I3DL2(tm) Listen/Src: No, No
Sensaura(tm) ZoomFX(tm): No