Ctrl Button Not Working

The left Ctrl button does not seem to be working; however, the right one does. This just occurred the other day and I only realized it when I attempted a Ctrl-Alt-Delete. Nothing happened. Rebooted and tried again - still nothing. Then I tried the right Ctrl button and it worked. I have also tried different sequences - Ctrl + Esc - onlt the right button works.

I have a Dell Dimension 8400 running Windows XP with the wireless keyboard.

Any thoughts and/or suggestions?