Dell Alienware M14x R2 (Early 2012) - Manual (Page 14)

Replacing the Base Cover
Procedure
1 Align the tabs on the base cover with the slots on the computer base and
slide the base cover until it snaps into place.
2 Tighten the captive screws that secure the base cover to
the computer base.
Postrequisites
1 Follow the instructions in "After Working Inside Your Computer" on page 13.
Base Cover 16