Right-click the Start button (lower-left corner), and select Apps and Features on the pop-up menu.
Select the Microsoft Office product you want to repair, and select Modify.
Note: This will repair the entire Office suite even if it’s just one application you want to repair such as Word or Excel. If you have a standalone app installed, then search for that application by name.
Depending if your copy of Office is Click-to-run or MSI-based install, you’ll see the following options to proceed with the repair. Follow the steps for your installation type.
In the window How would you like to repair your Office Programs, select Online Repair > Repair to make sure everything gets fixed. (The faster Quick Repair option is also available, but it only detects and then replaces corrupted files.)
In Change your installation, select Repair and then click Continue.
Follow the instructions on the screen to complete the repair.