Eu sinto que essa configuração deve estar em algum lugar no registro
There is a registry entry which contains (but not controls) the current slideshow duration in miliseconds. It is
HKEY_CURRENT_USER\Control Panel\Personalization\Desktop Slideshow\Interval
You can change it, but the next time you use the theme, the duration will be 15 minutes again. That duration is copied from:
%USERPROFILE%\AppData\Local\Microsoft\Windows\Themes\theme_name\theme_name.theme
(a text file) where there is an item named Interval near the end of the file. You can change the value of that entry to, say:
Interval=14400000
which is 4 hours, or any other value. But I do not know where the 15 minutes duration comes initially from.
Chaves do Registro do Windows 7/8 Wallpaper (Slideshow) , respondidas por Aplicativos