The ornamental design for a notebookcomputer, as shown and described.
FIG. 1 is a perspective view of a notebook computer, showing our new design;
FIG. 2 is a 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 plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a front-top perspective view thereof, showing a display part of the notebook in an open position.
Broken lines shown in the drawings illustrate portions of the notebook computer, and form no part of the claimed design, and the shade lines in the figures show contour and not surface ornamentation.