Windows keeps track of your most recently opened documents. For security and privacy's sake, you might want to clear out this list every so often.
Step1
Right-click on an empty space on the taskbar and click on 'Properties.'Step2
Click on the 'Start Menu' tab.Step3
Click on the 'Customize' button.Step4
Click on the 'Advanced' tab.Step5
At the bottom, under 'Recent Documents', click on the 'Clear List' button.Step6
Click on 'OK' twice and your list will now be cleared. 
