i bet sticky keys is turned on by accident. hold down ctrl or shift for like 8 seconds and it will give you a pop-up about sticky keys. disable them.
you can also turn them off by going to the control panel > accessibility options. uncheck all the boxes on the Keyboard tab (Use StickyKeys, Use FilterKeys, Use ToggleKeys). Then go into the settings for each one and uncheck the box that says "Use shortcut". Click Ok and your done.
'01 Bullitt #0054