ONE OF MY USB PORTS STOPPED WORKING ON MY DELL LATITUDE D600 PC NOTEBOOK.

A shot in the dark here, but try this: Click Start>Run, type devmgmt.msc and press enter. Click the plus sign beside "Universal Serial Bus Controllers." Right click each listing that appears underneath "Universal Serial Bus Controllers" and click Uninstall. Click OK on the confirmation dialogs. After you get done uninstalling all of them, restart your computer and Windows should reinstall them. After it is done, try that USB port again.

Usually if a single USB port stops working its actually the systemboard not a driver, all USB drivers are really part of the OS these days unless its USB 3.0 or even 2.0 if the os laptop is newer than OS. sorry for bad news

Your USB ports on your Dell computer are plug and play. If you have issues with your USB port, it is port related, driver related or device related. The following solutions will help you identify the problem to resolve your USB port issues.
To Identify a Working USB Port
Begin troubleshooting your USB ports by checking Device Manager to see if your USB ports or hubs are working properly.

1. Click the Start button. ClickControl Panel.
2. ClickSystem and Maintenance.
3. ClickDevice Manager.
4. Double-clickUniversal Serial Bus controllersand check to see if all your USB ports, hubs and controllers are functioning correctly. Any devices not functioning will have a yellow exclamation mark in front of them.
5. If Device Manager shows any USB ports, hubs or controllers are not functioning, check for updated drivers.

To Update the USB Port Driver

• Information onHow to Download and Install a Driver

• Watch a Video on Steps to Update Bios on Your Computer.
1. When the update process is complete, your computer will restart again to load the operating system with the new driver version installed.

To Run a Diagnostic Test on your USB Port

1. Go to theDell PC Diagnosticpage
2. UnderChoose a Diagnostic Type, selectHardware.
3. Using the scroll bar on the right-hand side of the window below, locate the listing for USB.
4. SelectUSB.
5. ClickRun Diagnostics.
6. Agreeto Terms and Conditions in Legal Statement.
7. Follow the instructions to test each USB port.