SSMS is not a free tool. It's the tool built by MS and designed to connect to and manage SQL Server. It's installed as part of the client tools, and may or may not be set up on your server.

However, when you connect to an instance with SSMS, it reads data from the system tables, the file system, and the registry on that server to determine how SQL Server is being run or is configured.

You should be using SSMS to administer your servers, not the registry.