CNG Key Isolation (KeyIso) Service Defaults in Windows 11
The CNG key isolation service is hosted in the LSA process. The service provides key process isolation to private keys and associated cryptographic operations as required by the Common Criteria. The service stores and uses long-lived keys in a secure process complying with Common Criteria requirements.
Default Settings
| Startup type: | Manual |
| Display name: | CNG Key Isolation |
| Service name: | KeyIso |
| Service type: | share |
| Error control: | normal |
| Object: | LocalSystem |
| Path: | %SystemRoot%\system32\lsass.exe |
| File: | %SystemRoot%\system32\keyiso.dll |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\KeyIso |
Default Behavior
CNG Key Isolation is a Win32 service. In Windows 11 it starts only if the user, an application or another service starts it. When the CNG Key Isolation service is started, it logs on as LocalSystem and running in a shared process of lsass.exe. If CNG Key Isolation fails to start, the failure details will be recorded into Event Log. Then Windows 11 should boot up and notify the user about the KeyIso service startup failure.
Dependencies
CNG Key Isolation cannot be started, if the Remote Procedure Call (RPC) service won't start.
If CNG Key Isolation doesn't work properly, the following services will not start:
Restore Default Startup Configuration of CNG Key Isolation
Before you begin doing this, make sure that all the services on which CNG Key Isolation depends are configured by default and function properly. See the list of dependencies above.1. Run the Command Prompt as an administrator.
2. Copy the command below, paste it into the command window and press ENTER:
sc config KeyIso start= demand
3. Close the command window and restart the computer.
The KeyIso service is using the keyiso.dll file that is located in the C:\Windows\system32 directory. If the file is removed or corrupted, read this article to restore its original version from Windows 11 installation media.