Dell Dimension 4300 - Manual (Page 10)

5. Press the two release buttons as you lift the cover.
The release buttons are located on the right and left sides of the computer as it is laying on its side.
Adding Cards
1. Shut down the computer .
2. Turn off any attached devices and disconnect them from their electrical outlets.
3. Disconnect the computer power cable from the wall outlet, and then press the power button to ground the system board.
4. Open the computer cover .
5. To raise the securing lever, press the tab until it is free from the latch and then lift the lever.
6. Insert the card into the connector.
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in " Safety Instructions ."
NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug it from the network wall jack.