Dell Dimension 5100 - Manual (Page 43)

5. Remove the screw that secures the front I/O panel to the front of the computer.
6. Pull the I/O panel toward the back of the computer and lift the panel to remove from the computer.
7. Disconnect any cables from the I/O panel.
System Board
Jumper Settings
The jumper locations are shown below.
1 screw
2 front I/O panel