The GPU driver package uses the standard Installshield switches, To perform a silent install do the following:
-Run the driver downloaded from www.NVIDIA.com.
-Select a location to unzip the driver contents to.
-Navigate to the selected location, ex: C:\NVIDIA\DisplayDriver\270.61\Vista 64-bit\English.
-Use the "Setup.exe" located here to perfom the silent install or create an .iss file with the following switch of "-s".
-Open up the command prompt, Drag the "setup.exe" into the command prompt or type the location of "Setup.exe" at the end add, one space and "-s" or "/s" to perform a silent/unattended install of the NVIDIA GPU drivers.
Note: You can run a silent install prior to unpacking the driver, but it will require you to select a location each time before the silent install will continue.