Go to the Dell support site, enter in the service tag of the unit, and it will take you to a list of all the drivers for that particular unit. Optionally you can select a specific model from a list.
u go to dell support.drivers/site they will be lots keep clicking on 1 after 2 till u get the right one, then find it select it then hit the download button, they will download to ur computer sent them to the downloads folder, that way u will have it for later..