Enabling the touch pad scroll feature on the Dell Latitude E5500 is accomplished by downloading the correct drivers. After some research on the issue, it seems that the problem is common, and that the fix is just a simple driver update, and ensuring that your trackpad is adjusted to the right settings under the "Mouse" menu in Windows. The Dell Latitude E5500 was seemingly shipped with dated drivers, so you'll have to update them to use the trackpad the way it was intended.
Click the Dell Support link (see Resources) to go to the Dell website to download the Latitude E5500 driver you need.
Select your operating system from the drop-down menu.
Under the "Input Device Drivers" sub-menu, you'll see the driver for "Touchpad/Pointing Stick." Click the "Download" button to download this driver.
Install the driver by double-clicking it if it doesn't auto-extract or pop up on its own.
Click the "Start" button.
Go to "Control Panel."
Click "Hardware and Sound." Depending on how you have your menus set up, you may be able to skip this step and just click "Mouse" in the next step.
Click "Mouse" or "Mouse and Trackpad Settings," depending on your version of Windows.
Click the "Scrolling" tab and make sure scrolling is enabled by clicking the box next to the option if it doesn't contain a checkmark already.