На 7 можно было вот ветка реестра.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Class{6BDD1FC6-810F-11D0-BEC7-08002BE2092F}\0000\Settings

The above key will show DWORD hexdecimal values like the following. It may have values something like the following.

0x00000005

Now this is a boolean value which means it’s either True or False. So any number that is not 0x00000000 is True which means the camera LED light will be active. If the hexadecimal value is 0x00000000 then the LED is turned off.