Installing and updating an Add-in for an Office application is not difficult. Honest, it's not. But the right steps have to be performed in the right order. The instructions here are for installing an Add-in on your computer (not in a shared location such as a shared drive, SharePoint etc) in the 'default' Add-ins folder ... Excel and PowerPoint share a default folder, Word and Outlook use their own distinct folders.
These instructions assume that:
You are using a Windows computer
You are using Office 2013 or newer (including Office 365) ... note that the exact text of some of the menu options, buttons and dialogs does change from version to version, these are based on Office 365 as of July 2022
Office is configured for the English language ... the process is the same for all languages, but you'll have to do your own translations of the names of the menu options and buttons listed in this guide
Windows is configured for the English language ... again the process is the same, but the name of the folder to use in STEP 3 can be different ... refer to the The Add-in folder you gave is missing for more info
If you're not sure whether the file you have is even an Add-in, they have the following file extensions:
For Excel: .xlam (.xla before 2007)
For Word: .dotm (.dot before 2007)
For PowerPoint: .ppam (.ppa before 2007)
For Outlook ... well, of course, Outlook is different ... the file must (normally) be called exactly VbaProject.OTM
If the 'Add-in' does not have one of these extensions then it is not an Add-in!
DISCLAIMER
Add-ins are powerful tools that can greatly enhance the functionality of an Office application. However, the VBA code that an Add-in contains can also wreak havoc with your data and your computer. In providing this guide, I am only informing you of HOW to install an Add-in, not WHETHER you should install a particular Add-in.
INSTALLING AN ADD-IN
STEP 1
So first download your Add-in or, if you received it via email, copy it out of the email and onto your computer. I recommend initially saving the file somewhere handy like your Desktop to start with.
STEP 2
This is the step that is often missed and IT IS A CRUCIAL STEP especially with the recent Microsoft announcement that Macros from the internet will be blocked by default in Office. You need to unblock the file.
Right-click the Add-in file on your Desktop (if you saved the file anywhere else, find the file using File Explorer and right-click on it), then select Properties, General … and in the ‘Attributes’ section you will see text similar to ‘This file came from another computer and might be blocked to help protect this computer’, check (tick) ‘Unblock’ and select Apply then OK (see screenshots below).
STEP 3
Next, the Add-in file needs to be copied to the default folder on your computer. As I said above, the default folder isn't the same folder for each application. The simplest way to get to the default folder is to copy the relevant one of the below file paths then paste it into File Explorer.
Add-ins for Excel and PowerPoint: %appdata%\Microsoft\AddIns
Add-ins for Word: %appdata%\Microsoft\Word\STARTUP
Add-ins for Outlook: %appdata%\Microsoft\Outlook
Copy everything from (and including) the first % to the end of the line and paste it into File Explorer in the 'folder path' box (at the top of the File Explorer window, or you can press Ctrl+L when in File Explorer to jump the cursor to the 'folder path' box) then press your Enter key. You should now be in the default folder (see the troubleshooting section if you get an error).
Now copy/paste the Add-in file into this folder (you can then delete the file from your Desktop).
STEP 4
If you are installing an Add-in for Excel, Word or PowerPoint then close and re-start it. You only have to do this for the specific application that the Add-in is for (all Add-ins only work in one application) and you don't have to re-start your computer.
Skip on to Step 5 for Outlook.
STEP 5
This step depends on which application you are installing an Add-in for. So I've broken it down:
For Word
You're done. That's it. Your Add-in will have loaded automatically when you re-started Word. If you were expecting new functionality / ribbon buttons / shortcuts etc then they should be loaded. Get yourself a cuppa.
For Excel
You now need to load the Add-in. In Excel, select: File, Options, Add-ins, Manage Excel Add-ins, Go.
In the list of 'Add-ins available', you should see your Add-in (it might have a different name here, these aren't file names) ... if you cannot see it, click Browse then select the Add-in (this time they are shown by file name) then Open.
Ensure the Add-in has a check (tick) next to its name then click OK, your Add-in will load and new functionality / ribbon buttons / shortcuts etc will be working. In future, the Add-in will load automatically every time you start Excel.
For PowerPoint
You now need to load the Add-in. In PowerPoint, select: File, Options, Add-ins, Manage PowerPoint Add-ins, Go.
In the list of 'Add-ins available', you may see your Add-in (it might have a different name here, these aren't file names) ... if you cannot see it, click Add New then select the Add-in (this time they are shown by file name) then Open.
Ensure the Add-in has a check (tick) next to its name then click OK, your Add-in will load and new functionality / ribbon buttons / shortcuts etc will be working. In future, the Add-in will load automatically every time you start PowerPoint.
For Outlook
Outlook always has to be different! In other Office applications, you can have multiple Add-ins. In Outlook, you can only have one. It 'normally' must be a file called VbaProject.OTM (the name is not case sensitive but uses this casing by default) so, first, check that the file you have copied into the Outlook folder is called exactly that.
Then you need to enable macros ... in Outlook select: File, Options, Trust Center, Trust Center Settings, Macro Settings then select either the recommended "Notifications for all macros" or the not recommended "Enable all macros". The difference is that with the former, you will see a notification every time you start Outlook (see screenshot below) whereas with the latter you will not. Your choice.
Now close and re-start Outlook.
If you have ever run an Add-in in Outlook before on your computer
Then the Add-in will load and (if you selected the "Notifications for all macros" option), you will see the above notification ... click 'Enable Macros', your Add-in will load and new functionality will be working. In future, Outlook will show you this same notification each time you start it.
If you have not run an Add-in in Outlook before (and you don't see the above notification if you selected "Notifications for all macros")
Then you need to 'jump-start' Outlook ... this only needs to be done once ... just (simultaneously) press Alt+F11 (that's the Alt key and the Function key 11) and you will see the notification ... click 'Enable Macros'.
Having done this, you will no longer see Outlook, you're in what's called the VBE ... this is where Add-ins are created. You don't want to be here ... and you certainly don't want to change anything in here or your Add-in will be toast. So just press the 'X' to close the VBE window (or select File, Close And Return to Microsoft Outlook) and you will be back to Outlook. While you were dealing with the VBE, your Add-in will have loaded and the new functionality will be working. In future, Outlook will show you the notification each time you start it but you won't have to do the Alt+F11 jump-start.
UPDATING AN EXISTING ADD-IN
Much simpler. First, close the application that the Add-in is for. Follow STEP 2 and then STEP 3 this time overwriting the existing Add-in file in the default folder (make a copy the existing Add-in file if you want to keep a backup and/or might want to revert to the older version at some point in the future). Re-start the application and your updated Add-in will be installed.
If you cannot see the new functionality / ribbon buttons / shortcuts etc then follow STEP 5.
TROUBLESHOOTING
While I said the process of installing an Add-in isn't difficult, there are plenty of things that can go wrong. This covers the main problems:
The Add-in folder you gave is missing
The folder in STEP 3 can have a different name for example if you use a computer configured for a non-English language (only some languages ... many still use the same name by default as for the English language), if you work in a managed IT environment (if your IT team choose to change it) or if you or another user have changed it (it is just a 'normal' folder and can be renamed). To find the right folder, follow these steps:
Excel (and PowerPoint, text in brackets is where PowerPoint is different to Excel)
In Excel (PowerPoint), select: File, Options, Add-ins, Manage Excel (PowerPoint) Add-ins, Go, Browse (Add New)
You are now seeing whichever folder is being used as the default folder for Add-ins. You can either:
Make a note of the folder ie from the 'folder path' box at the top of the 'Browse' ('Add New PowerPoint Add-in') window then browse to it in File Explorer, or
Navigate up the folder path one level using the 'up arrow' to the right of the 'folder path' box. You are now in the folder that contains the default folder ... right click the name of the default folder then select Send To, Desktop (Create Shortcut) ... close the 'Browse' ('Add New PowerPoint Add-in') dialog and the 'Add-ins' dialog. Double-click the shortcut you just added on your Desktop to open the default folder.
Copy/paste the Add-in file into this folder. Continue on with STEP 4
Word
In Word, select: File, Options, Advanced, scroll down to the 'General' section then click on 'File Locations'. Under the File Types heading, look for 'Startup'. The folder path to the right of this is the folder you need to copy the Add-in into. If you cannot see the full path (as the window showing the paths is narrow), highlight it then click Modify ... you are now seeing whichever folder is being used as the default folder for Add-ins. You can either:
Make a note of the folder ie from the 'folder path' box at the top of the 'Modify Location' window then browse to it in File Explorer, or
You can navigate up the folder path one level using the 'up arrow' to the right of the 'folder path' box. You are now in the folder that contains the default folder ... right click the default folder then select Send To, Desktop (Create Shortcut) ... close the 'Modify Location' dialog and the 'File Locations' dialog. Double-click the shortcut you just added on your Desktop to open the default folder.
Copy/paste the Add-in file into this folder. Continue on with STEP 4
Outlook
Outlook always uses the same folder. There is no way to change it and there is no where to go in Outlook to get it to show you confirmation of the folder (if you're reading this and you know better, let me know!).
I followed the instructions but the Add-in just doesn't load
First, make sure you unblocked the file ... see STEP 2. In my experience, the majority of the time when an Add-In won't run (including if it runs once and then not again), it is because the file is still blocked.
If you're sure the file is unblocked, continue with the following section ...
Settings that can block Add-Ins from running
Within Excel, Word, PowerPoint or Outlook (not each of these 4 has all of the same settings), try the following ... I have written these as if for Excel, if you're following this for Word, PowerPoint or Outlook then substitute that applications name where relevant and skip any settings that don't appear in that application.
If you make any changes as a result of any of the following, close and re-start your application to see if the Add-in loads. If you can see these options but they are 'greyed-out' then see the following Group Policy section.
File > Options > Add-ins > Manage > Add-ins > Go ... if you cannot see the Add-in in the list then it is not installed. Click Browse (Excel) / Add New (PowerPoint) and see if you can see the Add-in file in the folder that appears. If so, select it and click Open, ensure it is checked (ticked) in the list, close the dialog
File > Options > Add-ins > Manage > Add-ins > Go ... if you can see the Add-in in the list and it is not checked (ticked) then tick it
File > Options > Add-ins > Manage > Disabled Items > Go ... if you can see the Add-in in the list then select it then Enable > Close
File > Options > Trust Centre > Trust Centre Settings > Add-ins – ensure that none of the following settings are checked (ticked):
"Require Application Add-ins to be signed by a Trusted Publisher" - unless you KNOW that the Add-in is signed and you KNOW that the certificate is trusted on your computer
"Disable notification for unsigned add-ins (code will remain disabled)" - unless you KNOW that the Add-in is signed
"Disable all Application Add-ins (may impair functionality)"
File > Options > Trust Centre > Trust Centre Settings > Macro Settings ...
Under the Macro Settings heading, try selecting "Disable all macros with notification"
You DO NOT need to select "Trust access to the VBA project object model" ... selecting this is a security risk and is not needed for Add-ins other than those that are going to dynamically create VBA code ... unless you are developing your own Add-ins, you do not need this - ever!
File > Options > Trust Centre > Trust Centre Settings > Message Bar ... ensure "Show the Message Bar …" is selected (not "Never show information about blocked content")
File > Options > Trust Centre > Trust Centre Settings > File Block Settings, for both "Excel 2007 and later Add-in Files" and "Excel Add-in Files" - ensure Open is NOT checked (ticked)
Group Policy
If you work in a managed IT environment then your Group Policy settings can block Add-ins from loading or block VBA code from running (or both). The only way to handle this is to speak to the person in charge of your IT policy, ask them, beg them, or bribe them, to change the Group Policy settings.