Dell Dimension 4500 - Manual (Page 15)

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. Lay the computer on its side so that the arrow on the bottom of the computer points up.
5. Locate the two release buttons shown in the illustration. Then, press the two release buttons as you lift the cover.
Adding Cards
1. Shut down the computer .
2. Turn off any attached devices and disconnect them from their electrical outlets.
3. Disconnect the power cable from your computer, 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.
7. Ensure that the card is fully seated in the connector.
NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug it from the network wall jack.
NOTICE: Ensure that there is sufficient space to support the open cover—at least 30 cm (1 ft) of desk top space.
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in " Safety Instructions ."
CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover .
NOTICE: To disconnect a network cable, first unplug the cable from your computer and then unplug it from the network wall jack.