The ornamental design for the portable computer security device, as shown and described.
FIG. 1 is a perspective view of a portable computer security device embodying the present invention.
FIG. 2 is a front view of the portable computer security device shown in FIG. 1.
FIG. 3 is a rear view of the portable computer security device shown in FIG. 1.
FIG. 4 is a left side view of the portable computer security device shown in FIG. 1.
FIG. 5 is a right side view of the portable computer security device shown in FIG. 1.
FIG. 6 is a top view of the portable computer security device shown in FIG. 1; and,
FIG. 7 is a bottom view of the portable computer security device shown in FIG. 1.
The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed design. No claim is made to the color, fabric or surface shading lines on the portable computer security device.