FIG. 1 is a front, top perspective view of a first embodiment of a portable computer 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 an additional front, top perspective view thereof, with the portable computer shown in an open position;

FIG. 11 is an additional front view thereof;

FIG. 12 is an additional left rear view thereof;

FIG. 13 is an additional left side view thereof;

FIG. 14 is an additional right side view thereof;

FIG. 15 is an additional top view thereof;

FIG. 16 is an additional bottom view thereof;

FIG. 17 is an additional 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 an additional 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 an additional 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 an additional bottom view thereof; and,

FIG. 49 is an additional front, bottom perspective view thereof.

The claimed design is shown in relatively bold lines. The relatively thin shade lines show contour and not surface ornamentation. The parallel diagonal shade lines represent a translucent surface. The broken lines are environmental and form no part of the claimed design.