If you cannot see Word 2013 in the Start Menu when you search for it, use the following steps to get it back.
We will need to repair Office! Click the Start Button > Control Panel > Programs and Features. Find Microsoft Office in the list, select it and then click Change.
Select Online Repair and then click Repair, and Repair again. If you have any Microsoft Office programs running, it will complain about it and ask you to close them. Save all your changes and close them yourself, and then click Try Again.
While you are waiting for Office to be repaired, you will get this stylish progress bar to stare at. Nice.