FIG. 1 is a front, top perspective view of a first embodiment showing our new design;

FIG. 2 is front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof;

FIG. 8 is a bottom, front perspective view thereof;

FIG. 9 is a second bottom, front perspective view thereof with a latch in an open position;

FIG. 10 is a front, top perspective view thereof, with the portable computer shown in an open position;

FIG. 11 is a front view thereof;

FIG. 12 is a left rear view thereof;

FIG. 13 is a left side view thereof;

FIG. 14 is a right side view thereof;

FIG. 15 is a top view thereof;

FIG. 16 is a bottom view thereof;

FIG. 17 is a front, bottom perspective view thereof;

FIG. 18 is a front, top perspective view of a second embodiment showing our new design;

FIG. 19 is front view thereof;

FIG. 20 is a rear view thereof;

FIG. 21 is a left side view thereof;

FIG. 22 is a right side view thereof;

FIG. 23 is a top view thereof;

FIG. 24 is a bottom view thereof;

FIG. 25 is a bottom, front perspective view thereof;

FIG. 26 is a front, top perspective view thereof, with the portable computer shown in an open position;

FIG. 27 is a front view thereof;

FIG. 28 is a left rear view thereof;

FIG. 29 is a left side view thereof;

FIG. 30 is a right side view thereof;

FIG. 31 is a top view thereof;

FIG. 32 is a bottom view thereof;

FIG. 33 is a front, bottom perspective view thereof;

FIG. 34 is a front, top perspective view of a third embodiment showing our new design;

FIG. 35 is front view thereof;

FIG. 36 is a rear view thereof;

FIG. 37 is a left side view thereof;

FIG. 38 is a right side view thereof;

FIG. 39 is a top view thereof;

FIG. 40 is a bottom view thereof;

FIG. 41 is a bottom, front perspective view thereof;

FIG. 42 is a front, top perspective view thereof, with the portable computer shown in an open position;

FIG. 43 is a front view thereof;

FIG. 44 is a left rear view thereof;

FIG. 45 is a left side view thereof;

FIG. 46 is a right side view thereof;

FIG. 47 is a top view thereof;

FIG. 48 is a bottom view thereof; and,

FIG. 49 is a front, bottom perspective view thereof.

The claimed design is shown in relatively bold lines. The portion of the portable computer shown in gray shading represents a metallic-looking surface that preferably contrasts with the black portions. The relatively thin shade lines show contour and not surface ornamentation. The parallel diagonal shade lines represent a translucent surface and the broken lines are environmental and form no part of the claimed design.