When I use a key I have to wait 3 secs (yes, I counted) for whatever letter or number to appear on screen. I know that the computer knows I am using the keyboard because if I press numlock for long enough, I get the message that you get when you press the numlock key for 5 seconds. I have checked the control panel, and my settings in ease of control all checks out (I have everything off, including filter keys). I know as a matter of fact that, although I've only had this problem since this morning, it is unrelated to any setting changes, because I've done a system restore to 2 days back.
1. Uninstall the keyboard driver.
2. Reboot the computer (yes without installing a new driver just yet).
3. When the computer restarts, it should look to install a new driver all on its own.
See if this resolves it. If not, you may want to plug in an external keyboard to see if that has the same problem. If it doesn't, then your laptops keyboard may have loose wiring inside. You can check (unless it is under warranty, then have the manufacturer look at it).
Worst case, if none of the above works, you need a new keyboard for the laptop