The ornamental design for a windowlockingdevice, as shown and described.
FIG. 1 is a perspective view of a window locking device showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is another perspective view thereof.
The broken lines showing of environmental structure are for illustrative purpose only and form no part of the claimed design. FIGS. 2-7 are shown in an enlarged scale.