Right-click on fsmainui.exe in Task Manager and select The correct, safe file should always be located in one of these folders:
As the UI host, fsmainui.exe is generally not a resource hog. You may see it using a very small amount of CPU (0-2%) and while idling in the system tray. If you ever see it spiking in CPU usage, it’s likely performing a scheduled scan or updating its virus definitions. fsmainui.exe
If you suspect the file is malicious (e.g., it is located outside the normal F-Secure installation folder), you should run a scan with F-Secure or another reputable antivirus program to verify its legitimacy. FS Protection PC 18.3 releases - F-Secure Community Right-click on fsmainui
: F-Secure often updates these components silently in the background, which can sometimes trigger temporary UI "tasks" or alerts in your browser. Recommended Actions If you suspect the file is malicious (e
: This often occurs during installation on Windows 11 if required system components (like .NET Framework) are missing or corrupted.
Paradoxically, a third-party firewall (not F-Secure’s own) might block fsmainui.exe from accessing the internet. This prevents F-Secure from updating virus definitions. If your antivirus shows "update failed," check if your external firewall is blocking this .exe.