If you’ve ever had a problem deleting a horizontal line in Microsoft Word, this post is for you. The answer is something of a trick, as the horizontal line is not a line (or a graphic), it’s a bottom border.
In Office 2013 go to the Design tab and look to the far right for the Page Borders button. Within the borders settings, click on the leftmost tab titled Borders (not Page Border), and then select the top left option of None.
That will delete the border (horizontal line) from the area in question.
In previous versions of Word the solution is similar, i.e. find the Borders and Shading option and delete that bottom border.