If you are thinking about moving from vCenter for Windows to vCSA, you can use the migration wizard that is fully integrated into the vCSA installation.

During the migration, new vCSA appliance and PSC will be provisioned with a temporary IP address.

Once the temporary appliance (or appliances if you have a dedicated platform service controller) is up and running, the migration wizard will connect to the source vCenter for Windows (and PSC) and migrate the configuration and all performance data to the new vCSA.

In the end, the migration wizard will disconnect the source vCenter Server from the network (if you run the vCenter server in a virtualized environment) and change the temporary IP address of the new vCSA appliance to the production IP address of the previous vCenter server.