Notes about the MCO file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The MCO file type is primarily associated with 'MSN Messenger' by MSN. Winks, let you send a Flash-like animation to the screen of the person you're chatting with. Select the Wink to send from a Winks toolbar button in the chat window. (Often very annoying.)