FIG. 1 is a front perspective view of my new design for a portable computer with a base and a lid, the lid being shown in an open position;

FIG. 2 is a front perspective view of the base thereof shown separately for clarity of illustration only;

FIG. 3 is a front perspective view of the lid thereof shown separately for clarity of illustration only;

FIG. 4 is a front perspective view of the portable computer of FIG. 1 with the lid folded over the base;

FIG. 5 is a top plan view of the portable computer of FIG. 4;

FIG. 6 is a left side elevational view of the portable computer of FIG. 4;

FIG. 7 is a right side elevational view of the portable computer of FIG. 4;

FIG. 8 is a front elevational view of the portable computer of FIG. 4;

FIG. 9 is a rear elevational view of the portable computer of FIG. 4;

FIG. 10 is a bottom plan view of the base of the portable computer of FIG. 1 or FIG. 4;

FIG. 11 is a front perspective view of a second embodiment of my new design for a portable computer;

FIG. 12 is a front perspective view of the portable computer of FIG. 11 with the lid folded over the base;

FIG. 13 is a top plan view of the portable computer of FIG. 12;

FIG. 14 is a left side elevational view thereof;

FIG. 15 is a right side elevational view thereof;

FIG. 16 is a front elevational view thereof;

FIG. 17 is a rear elevational view thereof; and,

FIG. 18 is a bottom plan view thereof.

The broken lines are shown in the views for illustrative purposes only and form no part of the claimed design.