Sets the default authentication level for applications that do not call CoInitializeSecurity.
Caution It is not recommended that you change this value, 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 this value 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 on setting process-wide security, see Setting Process-wide Security.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole LegacyAuthenticationLevel = value
This is a REG_WORD value that is equivalent to the RPC_C_AUTHN_LEVEL constants.
If this registry value is not present, the default authentication level established by the system is 2 (RPC_C_AUTHN_CONNECT).