A. The system stores the usual background wallpaper bitmap in the HKEY_CURRENT_USER\Control Panel\Desktop\Wallpaper registry key. If you've enabled Active Desktop and selected a different background picture, such as a JPEG, the system stores this wallpaper in the HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Desktop\General\Wallpaper registry key.

As with a standard wallpaper, with the Active Desktop wallpaper, you can tile the wallpaper by setting the value TileWallpaper to 1, and you can center or stretch the wallpaper by setting the WallpaperStyle. A value of 0 centers the wallpaper; a value of 2 stretches it. When you first log on, the system displays the standard wallpaper until all processes start and the Active Desktop is enabled.