If the new version of the product is functioning properly, all data has been migrated to the new version, and all services are functioning properly, you should uninstall the previous version of the product.
Uninstalling the previous version of the product will prevent conflicts if the previous version is started by mistake while 10.1.2 is running. Chapter 9, “Performing an Uninstallation,” provides more information.
Uninstall will display errors if services were installed by the installation program when the old version was installed, but were removed manually in a later step. The uninstall process will display errors because it will not find the services when it tries to remove them.