Notepad++ does not recognize Drupal module code files (.module) as php source code files, so php syntax highlighting is absent for these files. In this post I will show you how to configure Notepad++ to recognize .module files as php source code files.
Open Notepad++ with root / administrator privileges. This is because the configuration changes will involve indirectly editing Notepad++’s core system files, which require root privileges to edit.
Go to Settings -> Style Configurator.
From the top portion, of the dialog box, select the theme for which you want to apply your style.
Select php from the language selection pane.
In the lower part of the dialog box is a list of the extensions that this theme recognizes as php source code files. Go ahead and add module as another extension. Save. If any module file is already open in Notepad++, close and reopen it.