Can you view the keyboard's status in device manager to determine the cause of the exclamation point? This should be in the properties. There should an error message (code xx) there that would be helpful in determining the cause of the issue.
Device Manager---- Keyboard Driver is missing or corupted. Window cannot locate keyboard driver.
there it is, download the keyboard drivers and you're all set
you might be able to just uninstall the keyboard using the device manager, and then reboot, and it would probably just reinstall itself, however, go ahead and make sure you have the latest drivers anyways, there could be bug fixes in them that might help prevent this in the future
Honestly, this is a standard keyboard and the windows driver should have worked. I'm assuming you used driver sweeper? If that didn't work, i'm starting to wonder whether your keyboard is just plain shot. They do sell replacement keyboards for your laptop. another option you can try is to system restore to a point before the problem started.
let dell detect your tag number (model), go to the downloads/drivers section, MAKE SURE YOU CHOOSE THE CORRECT OPERATING SYSTEM, and then go to the input section. if there is no keyboard driver, and only a touch pad driver, then they are bundled together. some do it that way, some dont.
download the touchpad driver. install.
if that doesnt work, then try system restore. if that doesnt work, then you have a hardware problem and need to take in or sent in for service.