If the tool fails to recognize your phone, open your PC's Device Manager. Check for missing drivers (yellow exclamation marks). Reinstall the Nokia Connectivity Drivers and try a different USB port (preferably a rear USB 2.0 port on desktops).
Flashing your device will erase all data and carries a risk of "bricking" the phone if the process is interrupted or the wrong file version is used. nokia c201 flash file
Ensure the tool detects your device.
Open the Nokia Flash Tool on your computer. If the tool fails to recognize your phone,
Fixes application crashes, white screen issues, and random restarts. white screen issues
Which your PC is running (Windows 10, 11, etc.)?