Try these steps in order:
Restart Windows, then launch from the Start menu.
Make sure it isn’t already running in the tray (end the task in Task Manager → Processes, then try again).
Run as administrator (right-click → Run as administrator).
Temporarily pause other antivirus/firewall, then start the app. If it works, add mutual allowlists and re-enable your AV.
If Windows shows a block: for SmartScreen click More info → Run anyway; if the file is “blocked” (Right-click → Properties), tick Unblock and apply.
Install the latest installer over your current copy (no need to uninstall).
Apply pending Windows updates and reboot.
Try Safe Mode (with Networking) and launch once from there; then reboot normally and try again.
If it still won’t launch, please send us details so we can pinpoint the cause: click Get help (or Let us know on the Scan Result screen) and include the Windows version, Gridinsoft version, any error message/screenshot, and diagnostic logs. We’ll investigate and provide next steps.