The Control Lock is actually a safety feature that allows the consumer to lock the control panel to prevent children from manipulating the controls and accidentally starting the appliance. This feature can often be set unintentionally and usually is not an indication of an actual problem with the appliance.
With the lock on, the control panel is disabled and you cannot use any of the controls, except the button to unlock it. It can inadvertently be set following a power outage, leaning against the control panel, or pressing and holding the wrong button. This is usually not an indication of a malfunction.
If this is a Whirlpool manufactured appliance (such as Kenmore Elite, Maytag Epic or Whirlpool Duet), the following link explains how to lock/unlock this feature:http://www.fixya.com/support/r3608801-control_panel_lock
These instructions are also printed on the front panel of the appliance and in the owner's manual.
If this does not correct your problem, then you may have a more serious problem other than a simple operator control button issue (such as an operator console problem or main control board issue). Please post back and let me know if you need further assistance.