My friend is going to look at a Range Rover p38 DSE which has a few niggles, the driver window and sunroof work fine but the read out on the dash says they are open all the time, what could be the cause of this?

Not set probably. When initially switching on ign, do you get the error message 'RH Front Window not set' or something similar? Ditto for sunroof? If so, when you get this message, raise window to top if it's not already, lower window to bottom, hold for a second and raise to top again. You should then get the message 'RH Front window set' or something similar. Do the same with the sunroof. That should then get rid of the window and sunroof open messages.