What is the origin of the ~ that just shows up on the
desktop? Is it harmful?
This a backup copy of the Address Book, it is created due to a
bug in Outlook Express.
The copy is usually created due to any action in the Address
Book (e.g. add or edit an address).
The ~ file can be deleted, or kept as copy of the Address Book
(give it a name with extension .wab to make it a usefull Address
Book again).