PYQT5 it could not find or load the Qt platform plugin "windows".

This error usually occurs when the required Qt platform plugin is missing or cannot be loaded. One possible solution is to make sure that you have the necessary dependencies installed on your system.

First, check if you have the Qt platform plugin "windows" available in your PyQt5 installation folder. You can find it in the "platforms" directory. If it's missing, you may need to reinstall PyQt5 or manually copy the missing plugin from another PyQt5 installation.

If the plugin is present, try setting the QT_PLUGIN_PATH environment variable to the appropriate directory. You can do this in your Python script before importing PyQt5:

import os
os.environ['QT_PLUGIN_PATH'] = 'path/to/plugins'

Replace 'path/to/plugins' with the actual path to the "platforms" directory containing the Qt plugins.

If the issue persists, it could be related to incorrect installation or configuration of PyQt5 and Qt. Make sure you have installed PyQt5 correctly and that the Qt libraries are accessible. You may need to uninstall and reinstall PyQt5 or Qt to resolve any underlying issues.

If none of the above solutions work, please provide more details about your environment and how you installed PyQt5.