how to delete a line in ms word?

Remove Existing Line From A Word Document

  

     Microsoft Word creates those lines as borders.  To remove the line:

1. Place the cursor in the line immediately above the line.
2. On the Home tab, click on the Border formatting menu.
3. Click on No Border.  See the screenshot below for the click path.

Alternatively, if you notice the line immediately after Word inserts it, you can click on the Smart Tag to see further options.  These include undoing the border line, and stopping automatic border line creation.  See the screenshot below for the Smart Tag button and its menu options.