Modifying the Security Defaults for a Computer
It is not recommended that you change the system-wide security settings, because this will affect all COM server applications that do not set their own process-wide security, and might prevent them from working properly. If you are changing the system-wide security settings to affect the security settings for a particular COM application, then you should instead change the process-wide security settings for that particular COM application. For more information about setting process-wide security, see Setting Process-Wide Security.
Certain values in the registry determine security settings for applications that do not call CoInitializeSecurity. You can modify these settings using Dcomcnfg.exe.
For more information, see the following topics: