The ornamental design for a notebookcomputer, as shown and described.
FIG. 1 is a front 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 view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a rear perspective view thereof.
The short- dash-long-dash broken lines shown in the figures represent the bounds of the claimed design, while all other broken lines are directed to environment and form no part of the claimed design.