Close outlook → Start Regedit
Navigate to HKLMsoftwaremicrosoftwindowscurrent versionpreview
handlers

Delete the key for Microsoft Word previewer  (or Excel or whatever you are having issues with).

Click on Start and then Control Panel.
After the Control Panel window opens, click on Uninstall a Program.
A list of all installed programs should now appear. ...
After the dialog box loads, choose the Repair option and click Continue.