By default, Windows Live Messenger, comes with its Aero border enabled. But if you want, you may also disable this aero frame, to give it a clean look.

To do so, open regedit and navigate to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Live\Messenger
In the right pane, create a new DWord AeroWindowFrameEnabled and give it a value ‘0‘.
This will disable the Aero border or frame.

Giving it a value ‘1′ will enable it.
Alternatively, you may also download these registry keys and add them directly to your registry.
Download: Enable / Disable Windows Live Messenger Aero Frame.
If you have liked this post, you might want to check out some more, on topics like Messenger, Registry, Tricks.