Software is installed and/or un-installed in networks. Each of a plurality of networks has a network management system storing metadata comprising at least the identities and command lines of software installed using installation systems of the management systems. On each network the network management system of the network is accessed to obtaining the metadata of items of software run on the network. That metadata is sent to a server which serves all the networks. At the server, a comparison is done to compare the metadata of instances of the same software on different networks. For those instances of the same software having the same metadata on different networks, the metadata is storing in a database. The networks use the metadata stored in the database to automatically install or un-install software.