Registry Values for System-Wide Security
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 are used to determine security settings for applications that do not call CoInitializeSecurity. You can use Dcomcnfg.exe to modify these default security settings for a computer. For step-by-step procedures that describe how to use Dcomcnfg.exe for this purpose, see Setting System-Wide Security Using DCOMCNFG.
Another way to change default system-wide settings is to manipulate registry values directly. However, only administrators and the system have full access to the portion of the registry that contains the default system-wide call-security settings. All other users have read-access only.
The named values that affect system-wide security defaults are as follows: