Unplug the keyboard for 10-15 minutes. After that it should be at factory default settings. If you're talking about keylocks, then just press the buttons.
You may have turned on the "StickyKeys" or "FilterKeys" Windows features on. To fix this press the SHIFT key 5 times or hold the shif key for 8 seconds.
You may restart the computer or use the mouse to reactivate the keyboard function. Keyboard under the Control Panel menu could be found, check all the boxes once you find Keyboard.