Not use pecmd.exe. Many peolpe mayb reply "set pecmd.ini".But I want set that by a base frame way. I try to change [HKEY_CURRENT_USER\Control Panel\Desktop\Wallpaper] to specify a image paper.When pe start,that image paper is shown,And then when explorer star,the wallpaper is changed to solid color background. I must manually set via control pannel to change wallpaper. How to set default wallpaper after start explorer in winpe