InstallAware

Our software test just reported the following case:

1. Our program is already installed on a system.
2. The user installs an upgraded version.
3. InstallAware performs an uninstall as a prerequisite.
4. During the installation of the update, something happens to cause a failure.
5. the install rolls back.

Once the rollback has occurred, the previously installed program is no longer present. While this makes sense to me, it would appear that Microsoft is indicating that the system should be rolled back to the same state that existed before the updated installer was run.

Could anyone provide additional information on this?

This is true if you are patching.

If you are installing a new version, Microsoft says you have to unstall the old version first, so rolling back during the install of a new version would be nothing installed.

You can code around this yourself by creating a copy of the installed files somewhere on the target machine, then if install fails copy them back.

This is a simple explanation but it shold get you started on the correct path.