) for the add-in and then choose Remove to remove that specific add-in. To remove a sideloaded add-in from Outlook, use the steps outlined in Sideload Outlook add-ins for testing to find the add-in in the Custom add-ins section of the dialog box that lists your installed add-ins. %userprofile%\AppData\Local\Packages\Microsoft.Win32WebViewHost_cw5n1h2txyewy\AC\#!123\INetCache\ If the following folder exists, delete its contents too. %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\ To remove all sideloaded add-ins from Excel, Word, and PowerPoint, delete the contents of the folder. To remove a sideloaded add-in from Excel, OneNote, PowerPoint, or Word on the web, see Sideload Office Add-ins in Office on the web for testing: Remove a sideloaded add-in.