Look above under Resources -> Tutorials, and in Software look for themes. It will tell you how to install.
You can get themes from www.pocketpcthemes.com,www.pocketthemes.comwww.pdagold.com and lot of other places.
Microsoft has a theme generator, look on the MS site for PPC and themes.
i know very well themes but i would like to change the white screen in the "Programs" folder (in which there are shortcuts of the installed apps).Themes change only the Today screen image and the colours of the bars....
Homever i thank you for your support.
Sorry, should have read your post more closely.
I am not sure there is a way to change the background you mention. Sort of like trying to change the background in similar windows on a desktop PC.