Try booting into safe mode (press F8 key) and follow the steps below:
I've had the same problems with Vista automatically updating device drivers. To prevent Vista from doing this, click Start -> right click Computer -> click Properties -> System and Maintenance -> System Protection -> then click the Hardware tab. Click Windows Update Driver Settings. Then click "Never check for drivers when I connect a device."
That should prevent Vista from automatically installing drivers for a device it does not recognize. If that doesn't work, unplug your modem or router from the computer.
Then try to uninstall whatever drivers Vista installed, reboot into safe mode, and install the most recent sound drivers for your board.
Hope that helps, Danny.
