You typically run into the reboot scenario when you are manually testing the uninstaller.
The SSI uninstaller requires a reboot when a file or folder, that is normally removed during the uninstall process, is locked/in-use when the uninstaller runs. If you have a command prompt window open and your current directory is set to one of the folders that would normally be removed during the uninstall process, then the install script cannot remove that directory. A reboot is required in order to delete the folder.
When using Windows' "Add/Remove Programs", the utility uses the full path to the uninstaller and the current directory is one of the system directories, not the uninstaller's folder.
When manually testing:
- Open a command prompt window.
- Make C:\ your current directory (or any other directory that would not be removed by the uninstaller).
- Run the uninstaller using the full path to the uninstaller. You might want to use a batch file to make this easier.