Hi, and welcome to the forums
The sponsor of plus is from C2Media. Anyway, try to uninstall messenger plus and restart your computer. If that CWT is still there you'll know for sure that that program is not the plus sponsor. You can get Adaware to remove it. In any case you can always install Plus again with or without the sponsor. It's your choice
Btw, the detailed instructions on how to remove the sponsor of plus are listed in
http://shoutbox.menthix.net/showthread.php?tid=21598
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