A lightweight, automated Windows script that solves the ms-screensketch protocol error on PCs with FnLock enabled, especially when the native Windows Snipping Tool is uninstalled or disabled. It allows Lightshot to trigger instantly with a single press of the PrtScn (Print Screen) key, without holding Fn.
On laptops or keyboards with FnLock active where the native Windows Snipping Tool is either uninstalled or disabled, pressing the PrtScn key (without holding Fn) fails to send a standard PrtScn hardware signal.
Instead, Windows attempts to trigger the system protocol ms-screensketch:. Because Windows cannot find the native app, it displays a popup error message, preventing Lightshot from capturing the screen.
This fix registers a seamless, invisible handler in the Windows Registry for the ms-screensketch protocol:
- Intercepts the
ms-screensketchcall triggered by pressingPrtScnwith FnLock enabled. - Executes a background VBScript/PowerShell command to silently trigger a real physical
PrtScnkey event. - Lightshot instantly catches the key event and opens the screenshot selection area.
The process is 100% invisible with no terminal or prompt window flashing.
- Download or clone this repository to your computer.
- Make sure Lightshot is running in your system tray (feather icon).
- Double-click the
Fix_Lightshot.batfile to apply the fix. - Done! Press
PrtScnanytime to capture your screen with Lightshot.
To remove the fix and restore the default Windows registry settings, open Command Prompt (cmd) and run:
reg delete "HKCU\Software\Classes\ms-screensketch" /f