Dell Latitude C540 - Manual (Page 45)

these precautions when using extended PC Cards:
Protect the exposed end of an installed card. Striking the end of the card can damage the system
board.
Always remove an extended PC Card before you pack the computer in its carrying case.
Install an extended card in the upper PC Card connector to allow room for a second PC Card.
Installing a PC Card
You can install a PC Card in the computer while the computer is running. The computer automatically detects
the card.
PC Cards are generally marked with a symbol (such as a triangle or an arrow) to indicate which end to insert
into the slot. The cards are keyed to prevent incorrect insertion. If card orientation is not clear, see the
documentation that came with the card.
To install a PC Card:
Hold the card with its orientation symbol pointing into the slot and the top side of the card facing up.
(If you have a push-button latch, the latch may need to be in the "in" position before you insert the
card.) 1.
Slide the card into the slot until the card is completely seated in its connector. 2.
If you encounter too much resistance, do not force the card. Check the card orientation and try again.
If you have a rotating PC Card latch (one that pops out beyond the edge of the computer when you
insert the card), rotate the latch closed after inserting the card.