CNG Service Defaults in Windows 7

Kernel Cryptography, Next Generation by Microsoft Corporation.

Default Settings

Startup type:Boot
Display name:CNG
Service name:CNG
Service type:kernel
Error control:critical
Group:Base
Path:%SystemRoot%\System32\Drivers\cng.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\CNG

Default Behavior

CNG is a kernel device driver. In Windows 7 it is being loaded by Boot Loader before Kernel initialization. If CNG fails to load, Windows 7 attempts to write the error data into Event Log and restart the computer, using the Last Known Good configuration. If the Last Known Good configuration is not valid, Windows 7 startup ends with a Stop error. If you remove or disable the CNG service, Windows 7 won't start.

Restore Default Startup Configuration for CNG

1. Run the Command Prompt as an administrator.

2. Copy the commands below, paste them into the command window and press ENTER:

sc config CNG start= boot
sc start CNG

3. Close the command window and restart the computer.

The CNG service is using the cng.sys file that is located in the %WinDir%\System32\Drivers folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 7 installation media.