The ornamental design for a notebookcomputer, as shown and described.
FIG. 1 is the front perspective view of a notebook computer showing my new design;
FIG. 2 is the front view thereof;
FIG. 3 is the rear view thereof;
FIG. 4 is the left-side view thereof;
FIG. 5 is the right-side view thereof;
FIG. 6 is the top-side plan view thereof; and,
FIG. 7 is the bottom-side plan view thereof.
The broken lines are for environmental purposes only and form no part of the claimed design.
The surface treatment of the notebook computer shown in the figures forms no part of the claimed design, a notebook computer according to the claimed design may have any surface treatment.