Delete the registry below will reset all settings in SmartFTP. Your favorites will not be affected by it and you can still access them in the menu: File - New Connection afterwards.
Close SmartFTP
Click on the Start button in Windows
Select Run...
Enter regedit.exe
Press ENTER
The Registry Editor opens
Delete the following registry key/folder HKEY_CURRENT_USER\Software\SmartFTP\Client 2.0
To delete it, select the Client 2.0 folder on the left side. Then press the Del key.