How to turn on Windows automatic lock after N minutes of inactivity through the registry?

Question

System administration

Interested only in a software solution, through a reg-file or something like that.
Windows 7 Ultimate

Answer 1

As a result, the following BAT file does what it needs, I checked it. Only restart of the machine is required (log-off did not check). Source

:: включаем скринсейвер; 
Reg add "HKEY_CURRENT_USER\Control Panel\Desktop" /v ScreenSaveActive /t REG_SZ /d 1 /f

:: после скринсейвера - блокируем вход
Reg add "HKEY_CURRENT_USER\Control Panel\Desktop" /v ScreenSaverIsSecure /t REG_SZ /d 1 /f

:: таймаут скринсейвера в секундах
Reg add "HKEY_CURRENT_USER\Control Panel\Desktop" /v ScreenSaveTimeOut /t REG_SZ /d 300 /f

Answer 2

here