MS Word comes in a bundle with Office Suite. It contains many other useful applications like Powerpoint, Excel, Access, and many more productive tools. Sometimes when you install any third-party applications they install add-on with MS Word to embed the features provided by that application.
The common example is Adobe Acrobat. To remove those addons, follow the following steps.
Click on the start menu and start typing MS Word. This will show MS Word on the top of the search result.
Click to open it. Once opened, click on the File menu.
Click on the Options list in the menu to open MS Word configuration options.
On the left menu in the options window, click on Add-Ins. This will show all of the installed Add-Ins linked with MS Word.
Click on the Go button next to Manage COM Add-ins option.
This will open install Add-Ins Window. Select the Add-In and click remove. This will remove the Add-In for that application.