The Sharing Folder feature of Windows Live Messenger is an alternative to the "direct transfer" method of file distribution. When a user wants to deliver a file to another person on his or her contact list, the "sharing folder" window appears, which is an individualized representation of all previously shared items.
When files are added to the "sharing folder" for that particular person, the file will automatically be transferred to the corresponding computer when they are online. This means that the folder is literally "shared" between two computers. If a user deletes a file, for example, the file will also be deleted from the corresponding computer's shared folder.
To minimize risk of virus-infected transfers, the "sharing folder" feature is bundled with an anti-virus program. The "sharing folder" feature can only be used on computers with NTFS-formatted hard disks.