This icon is a shell folder used to share files between your friends that also use Windows Live Messenger. Since I never use this feature, it’s good that there’s a simple registry hack to remove it, similar to the hack to remove the Web Folders icon.
Manual Registry Hack
Open up regedit.exe through the start menu search or run box, and then browse down to the following key:
Below that key you will find a key with the name {FC9FB64A-1EB2-4CCF-AF5E-1A497A9B5C2D}, and all you have to do is delete it, preferably after exporting a copy of the key just in case.
Hit refresh in Computer and you’ll see that the icon is gone. To restore it, use the download below.
Download Registry Hack
Just download, extract, and double-click on RemoveMessengerSharingFolders.reg to enter the information into the registry. The icon should now be gone. To restore, just use the RestoreMessengerSharingFolders.reg file instead.
Download RemoveMessengerSharingFolders Registry Hack