Possible to Change Screen Resolution with Script?
ResSwitch is a utlity that will do what you want. Its a command line tool that you send the resolution, colour depth and refresh rate - e.g
resswitch.exe 800 600 32 60
You can use the device switch to specify which device the command applies to, specifying the name of the device. So for 4 monitors you'd probably be best creating a batch file with 4 commands in.
To get the names of the devices you can use ResCopy, also included in that zip file to display them.