The ornamental design for a computerkeyboard, as shown and described.
FIG. 1 is a front perspective view of a computer keyboard showing my new design.
FIG. 2 is a top view thereof.
FIG. 3 is a bottom view thereof.
FIG. 4 is a front side view thereof.
FIG. 5 is a back side view thereof.
FIG. 6 is a right side view thereof; and,
FIG. 7 is a left side view thereof.
The broken lines shown surrounding the outer most perimeters of the keys are understood to represent the bounds of the claimed design, while all other lines are directed to environment and form no part of the claimed design.