I am on Windows 10 and I just ran Windows Update. Most updates were for MS Office 2013, but 1-2 were for Windows. Those 1-2 for Windows are known to cause reboots. During update process, my PC did reboot and upon booting it said that updates were not properly installed. Then it installed them again and all seemed fine, except MS Word and WINWORD.EXE do not work now... Excel and PPoint work fine. What's going on? Re-install MS Office???
Not broken here, but standard procedure is go to Programs and Features, find the broken application, choose "Change" then select the repair option.
I re-installed and it seems like it worked. I accidentally typed Office 2015 - its actually Office 2013...