This is one of the biggest challenges for an amateur photographer. Some Minolta Dynax/Maxxum 7D had (and sometimes still have) problems of imprecise autofocus. Usually, the solution is to send the camera back to the Minolta (now Sony) repair shop.
But there is some available data to do it by yourself. If you are not faint of heart, you can setup your AF adjustment. You have to be technically inclined but the information is available.
Pages from the Minolta repair guide
As usual, just click on the small images to open them in larger (readable) size.
The original web site:
Maxxum AF 7D Adjustment de PGanzel.
Personally, I would not try it before everything else failed, but…