Versions 3.17 and below offered the following MSIs:

• Machine MSI installer
• User MSI installer

Versions 3.18 and above offer the following MSIs:

• MSI for per-machine installation
• MSI for per-user installation during user login
• Fix for sign-in issues

Deployments using the old machine MSI installer should consider migrating to the new MSI for per-machine installation.

Deployments using the old user MSI installer should consider migrating to the new MSI for per-user installation during user login.

IT administrators can also choose to change the deployment type from per-machine to per-user, or vice versa, if desired.

It is recommended to uninstall the old MSI if you are upgrading the user MSI or planning to switch the type of MSI being deployed.

If a deployment is using the old machine MSI installer, the new MSI for per-machine installation will upgrade the old machine MSI. In this situation, the old MSI does not need to be uninstalled first.

In all other cases, migrations involving per-user installation, or migrations which change the deployment type from per-machine to per-user, or vice versa, should perform a full uninstall of the old MSI first.

Here is a table of the possible migration strategies:

From type of MSI version 3.17 and below	To type of MSI version 3.18 and above	Possible migration strategies
Machine MSI installer	MSI for per-machine installation.	Uninstall the old MSI before installing the new MSI. Let the new MSI upgrade the old MSI.
Machine MSI installer	MSI for per-user installation during user login.	Uninstall the old MSI before installing the new MSI.
User MSI installer	MSI for per-machine installation.	Uninstall the old MSI before installing the new MSI.
User MSI installer	MSI for per-user installation during user login.	Uninstall the old MSI before installing the new MSI.