Nina,

Thank you for using the Dell Community Forum.
Is the USB hub a powered hub?
Here are some steps you may want to try:
---------------------------------------------------------------------
1.Turn off power management for the USB ports.
Right click My Computer, click Properties.
Click on the Hardware Tab, Device manager button.
Left-click the plus (+) sign next to Universal Serial Bus Controllers.
Right click USB Root Hub or USB 2.0 Root Hub, click properties.
Click the Power Management tab.
Uncheck the box for: "Allow the computer to turn off this device to save power"
Click Apply and OK.
You need to perform this step for each listing of USB Root Hub or USB 2.0 Root Hub.

2.If your system came with a Bluetooth wireless card, try disabling the card in the system bios.

3.Test other USB devices like a keyboard, mouse, memory stick, to see if the USB ports are working.

5.Try removing and redetecting the USB hardware.
---------------------------------------------------------------------
Click the Start button, from the menu point to Settings, and then click the Control Panel option.
Once in the Control Panel , double-click the System icon.
The System Properties window appears.
--For Windows 95, 98, and Me , click the Device Manager tab of the window.
--For Windows 2000 and XP , click the Hardware tab of the window.
Once at the Hardware tab, click the Device Manager button located in the center.

Highlight the USB ROOT HUB icon in Device manager.
Right-click the USB ROOT HUB and click Remove or Uninstall.
A Confirm Device Removal window appears.
Click OK.
Physically remove any devices that are plugged into the USB ROOT HUB.
Close the Device Managerwindow.
Click Start.
Click Shut Down.
Select Shutdown.
Click OK.
---------------------------------------------------------------------