You don't actually need to install the drivers for your monitor but if you really want to go to:
Control Panel/System/Device Manager/Monitors then click the + box and observe the text there it will probably say 'Generic P & P Monitor' or similar.
Right click on the text and select Properties. Select the driver tab, click on update driver then browse to your inf file and select it. It will then either install or Vista will tell you again it doesn't need it.
The resolution choice is actually determined by your graphics card drivers. Install the latest drivers from
www.nvidia.com then select the nearest resolution to 1680 x 1050 that you have an option for. 32 bit colour and usually 60Hz refresh rate.
Just because LG recommend that resolution it isn't critical. If it looks good, accept it.