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 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. In some embodiments, certain portions of the design, such as the hinge, keys and feet, may be black. 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. All broken lines represent environmental subject matter that forms no part of the claimed design.