When you want all of the applications on one computer that do not provide their own security to share the same default security settings, you would enable security on a machine-wide basis. Using Dcomcnfg.exe makes it easy to set default values in the registry that apply to all applications on a machine.
It is important to understand that if the client or server explicitly calls CoInitializeSecurity to set process-wide security, the default settings in the registry will be ignored and the parameters to CoInitializeSecurity will be used instead for the security settings for the process. Also, if you use Dcomcnfg.exe to specify security settings for a particular process, the default machine settings are overridden by the settings for the process.
When enabling machine-wide security, you must set the authentication level to a value other than None, and you must set launch and access permissions. You might want to set the default impersonation level, and you can set secure reference tracking, if you wish. The following topics provide step-by-step procedures: