Sorry, I should have given more complete instructions.
Select the graphic. Look for the Picture tools tab that should appear above the ribbon, over towards the right. If word is not maximzed on your screen, such "super tabs" may be harder to see. Select the Pciture tools tab and click on the Text wrapping button in the Arrange section. Set Text wrapping to "In line with text."

This will put the graphic in it's own paragraph. Create the borders your want. Then, with the graphic still selected, return to the Text wrapping menu and select square. You can then position the graphic manually where you would like it in a paragraph.

Depending on the type of image, there may be other adjustments you can make, adn these you can look up.

Best,
Ulodesk