On Windows, open Registry Editor
Go to `HKEY_LOCAL_MACHINESOFTWAREPoliciesGoogleChrome`
If the `Chrome` key does not exist, create it
Create a new `DWORD (32-bit) Value`
Name it `IncognitoModeAvailability`
Set its value to `1` to disable Incognito mode
Restart Chrome
On Mac, open Terminal
Run `defaults write com.google.chrome IncognitoModeAvailability -integer 1`
Restart Chrome
On ChromeOS, use the Google Admin console
Go to the Chrome policy settings
Set Incognito mode to disabled
Apply the policy to the desired users or devices
To re-enable Incognito mode, set `IncognitoModeAvailability` back to `0` or delete the policy value