Lt. Commander Data on "Star Trek: The Next Generation" had a secret button between his shoulder blades that would reset him if pressed. Your Dell Latitude E6500 has something very similar with the Dell Factory Image Restore partition included on the hard drive. With this "secret button" you can reset the computer to the exact settings and configuration it had when it rolled off the factory line at Dell. It will delete all of your data, so back up your information first. The factory restoration will reset the computer to the operating system it shipped with from the factory, be that Windows XP, Vista or 7.
Shut off your computer. Hold the power button down to restart the Latitude then press "F8" on the keyboard until you see the "Advanced Boot Options" menu.
Choose "Repair Your Computer" from the list. Select the language you want to use in Windows then click "Next." Enter your username and password then click "OK." Click "Dell Factory Image Restore."
Click "Next" then accept the warning that you will delete all the information on the computer by doing this. Click "Next" again. When the restoration is complete click "Finish." The computer will reboot into a factory-fresh state.