Pressing Ctrl/Alt/Delete will not bring up logon screen.

Hi, I have an EliteBook 8460 running Windows 7 the keyboard on the laptop will not work. Pressing Ctrl/Alt/Delete will not bring up logon screen. But if I put it into the docking station it works.
Last night I tried to plug an external keyboard into the USB port and it still would not work, but today a plugged it from turned off started it and the external keyboard worked but the laptop keyboard is not.
Have I somehow locked my keyboard? Does anyone have any ideas what the problem could be.