No sound device after every restart

The onboard sound chip is an ALC650 Realtek or Avance, can someone tell me how the operations and what is AC97 ? It comes with a yellow question mark is detected and the driver on the ASUS homepage can then install the device manager, sound funzt, everything wonderful. Up to a restart. Thereafter, the audio controller in Device Manager is still there (!), But in "Sounds and Audio Devices" is that no device was available. Sounds are disabled and the Avance own tool in the mixer tray is there, but doing nothing when one makes a double click ...

I have the audio controller is removed and the INF file in Windows \ Inf folder, and also at the next reboot the drivers reinstalled. Without the INF file to delete the drivers installed when Windows restarts itself a new and sound still does not. Drivers without rebooting install I have not tried.

hi,
I have a modified Windows XP CD used in the setup by some services disabled or set to "Manual" are asked. However, I have not checked all, otherwise I would have seen that "Windows Audio" Manual is on ... Must be set to Automatic and everything is OK.

In System Information via desktop all programs>Accessories>System tools>Components>Problem devices are their any problems listed? Conflicts? Sharing? Related to your issue?

Check that audio is set to start automatically....

Go to Start>> Run>> type in services.msc. A window will pop up with a list of services. Scroll down to Windows Audio>> Select and right click>>Select Properties. Under the 'General' tab Make sure that 'Startup' is set to automatic. Click Apply and okay...Now check the startup status under services..Make sure it says started. If not look to the left and click start service...