Can I change the default Windows Background?

A. Using the Registry Editor (regedt32), edit the key HKEY_USERS.DEFAULTControl PanelDesktop and double click the Wallpaper Key, and enter the value including directory (e.g. c:winntsavlogo.bmp).You can also change the background colour HKEY_USERSDEFAULTControl PanelColors, double click Background, and change value (e.g. 0 0 0 for black).