I claim the ornamental design for a personal computer, as shown and described.
FIG. 1 is a top perspective view of a personal computer of the present invention;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a rear view thereof.
The broken lines surrounding the elevated portion appearing on the front of the panel in FIGS. 1 and 2 define the bounds of the claimed design and form no part thereof. The other broken line showing of the personal computer is included to illustrate portions of the computer and form no part of the claimed design.