There are 2 steps you can do to fix the problem
1. Change the USB Emulation Setting in the BIOS
NOTE: It is recommended to disconnect any USB devices before performing the following steps.
Restart the system.
Wait until the Dell Logo appears.
At the Dell Logo screen, press F2 right away to enter the System Setup.
The System Setup screen will appear.
Press the down arrow key to highlight Integrated Devices (LegacySelect Options).
Press Enter.
A small box with a list of devices appears in the middle of the screen.
Press the down arrow key to highlight USB Emulation.
The default setting is On.
Press the Space Bar on your keyboard to change the setting to No Boot.
Press the Esc key.
The small box disappears.
Press the Esc key again.
A small box with list of options appears in the middle of the screen.
Make sure that Save Changes and Exit is highlighted in blue.
Press Enter.
The system will then restart.
The recommended changes have now been made to the BIOS.
2. Reset the Dell Dimension desktop System Setup (BIOS) to factory defaults.
Restart the system.
The Dell logo screen appears.
Press F2 to enter the System Setup (BIOS).
The System Setup screen appears.
Press the ALT + F key combination.
Press the Esc key to Save and Exit.
Press Enter to Save changes and exit now.
The BIOS is now set to the default settings.