I use a Dell LATITUDE E6400 laptop with Windows 7 . Both control keys dont work most of the time and I have to connect a keyboard (USB) in order to work. Also, the FUNCTION key doesn't work many times and then, all of a sudden it starts working. HELP.
If the external keyboard works the I suspect you have a mechanical problem with the internal keyboard. It is relatively easy to replace the laptop keyboard. Ebay is often a good place to find replacement keyboards.