After Starting Windows there is no sound

[artiom]

Hi, i'm getting really annoying with this problem, as i can't get rid of it since months. When i start my windows there is no sound. When i turn it off and turn it again on(restart doesn't help), sound works properly. I have audio build into the motherboard. So i've checked, the sound is not muted, i can't play any file, i don't hear boot-up neither shut-down signal. There is no sound driver in the device manager. i go to Add Hardware Wizard and install the VIA AC'97 Audio Controller manually. It's been installed but the it cannot start( the device may not work correctly Code 10). I uninstall this driver, and turn windows off then turn it on. Device manager has a new sound driver Vinyl AC'97 Codec Combo Driver. The sound works properly. But not for a long. The next time i start windows the driver is gone and there is no sound. I've tried to reinstall windows. I had installed the Vinyl AC'97 Audio Codec from drivers and utilities disk. But this problem continues. What should i do?

Thanks for advises