- ClickOnce deployed applications, by principle, are installed per user and not per machine (i.e. all users), which enables Add-Ins to isolate and not affect other Add-Ins.
- Installation and updates can be pushed via a web share or a network, however the admin chooses to.
Despite the above benefits, if you still want to install the office Add-In for all users:
- You can use an alternate installer technology such as Windows Installer, and obviously the installer will require administrator privileges.
- You will lose the automatic update benefits and would have to consider an alternative process or implementation
- There are caveats of deploying Office Add-Ins for all users, such as, end users running with standard user privileges cannot install/uninstall or disable an Add-In.
If such an Add-In fails/crashes unexpectedly resulting in the host Office application crashing, the end user cannot do anything to stop the Office application from crashing because they cannot disable the Add-In causing the crash.