Question Windows 7 Wallpaper changer

[Zexor]

I have windows 7 background setup as a slideshow to change picture every 30 min. But when i use SystemParametersInfo in my program to set the wallpaper so i can see how it looks on screen, the wallpaper no long change like a slideshow. How can i display an image in the background but keep the current desktop background setting unchanged so that it will stay a slideshow on the location it was set?

 

[Zexor]

I think it save the slideshow info in the slideshow.ini in the appdata theme dir. looks like if i preserve that file, it preserve the slideshow