When a service window is created on one site in a System Center Configuration Manager hierarchy, service windows on all other sites in the hierarchy are deleted.
For example, after you create a service window for the Central Administration Site (CAS), a new service window is created for the child primary site. But after this second service window is created, the first service window that you created for CAS is automatically deleted.
After you install this hotfix, each site can have its own service window. However, previously deleted service windows will not be restored.