Disable Start up Menu in Window 7.

 
Step-1    Right Click on the Taskbar.

Step-2    Click on Properties.

Step-3    Click on Start Menu.

Step-4    Uncheck 

                 Store and display recently opened programs in the Start menu.
     
                 Store and display recently opened item in the Start menu and the taskbar.

Step-5    Click Apply.

Step-6    Click ok.