Notes about the MCO file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries
, unused processes and other unfavourable system settings to identify slowdown issues.
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.)