Re: USB connect/disconnect sound and monitor blinking after start windows or game -GT
The newer Nvidia drivers have an option to "clean" or remove all old drivers and install the new ones. Try that. Also, make sure you have a driver for your Benq. It may have trouble syncing or connecting to the monitor when changing resolutions.
You can also try another VGA/DVI cable or adapter. A bent bin could cause issues.
Lastly, trying updating your Direct X, which is updated several times a year. Look for dxwebsetup.exe from Microsoft and update Direct X.