This file started appearing on people's desktop after the April 2003, Cumulative Patch for Outlook Express (330994) update released by Microsoft. If that update is installed and you take any action that changes the Windows Address Book the tilde file will appear on your desktop.
You can find out more about the update itself from this Microsoft page
When you change the Address Book, what should happen is that a backup called YOURNAME.WA~ would be created in the directory C:\Windows\Application Data\Microsoft\Address Book. This is a backup to the Address Book named YOURNAME.WAB in that same directory. With the update installed, however, the backup does not get installed into the correct directory and the name gets shortened to just the ending tilde (~) character. This file appears on your Desktop instead of where it should appear.
You have four options to "fix" this:
- Uninstall the patch. If you do this you may open your computer to the security problems that the patch fixes. And, Windows Update will notice that the patch is not present and, depending on how you have Windows Update configured, may reinstall it automatically or ask you to allow it to reinstall it. You will have to tell Windows Update "no" if you don't want to continue having the tilde file on your Desktop.
- Leave the patch installed and simply delete the tilde (~) file every time it appears. If you do this the consequence will be that you don't have a current backup of your Windows Address Book. Having this backup may or may not be important to you.
- Leave the patch installed and move/rename the tilde (~) file every time it appears. While this would be the safest option it is also the one that requires the most work. You will have to rename the tilde (~) file to YOURNAME.WA~ (substitute your login name for YOURNAME) and then move the file to the C:\Windows\Application Data\Microsoft\Address Book directory and have it overwrite the file of the same name there.
- Change the startup directory so the file appears elsewhere. If you right click on the Outlook Express shortcut and choose Properties from the menu you will be presented with a dialog box. One of the entries in the dialog will be "Start In:". Change that entry to read: C:\Program Files\Outlook Express\ and the tilde file should then be created in that directory instead of on the desktop. You should also change the shortcut in the Start|Programs menu the same way so the tilde files won't be produced there either. This won't solve the problem, of course, but it puts the file where you don't have to be bothered by it and, since you know where it is, can recover it if need be.
Microsoft is supposed to be aware of the problem and will likely eventually fix it (perhaps in a new version of the program instead of an update).
If you're not certain, rename the file to TEST.WAB and move it to the indicated directory above. Then double click it and see if the Address Book applet in Windows starts and shows your address book.