So here is the deal, I changed my log in wallpaper (http://ipadwallpapersbybay.com/images/osx-lion-login-ipad-wallpaper.jpg) to my own, Created my own wallpaper for my log in screen made sure all settings are the same 1280x800, 72ppi. placed it in the correct folder (/System/Library/Frameworks/AppKit.framework/Versions/C/Resources) changed the gray wallpaper named NSTexturedFullScreenBackgroundColor.png with my wallpaper with the same name. So it should work right? But when ever i restart or shut down and my mac goes to log in sceen i see the same old gray wallpaper, even though i have replaced the file. I have checked the folder if the picture in there have been changed back to gray, but i see my picture. Strange. I even tried using app called Lion Designer (http://www.macupdate.com/app/mac/40594/lion-designer/) doesnt work So my question is how to fix/change the gray wallpaper, changes back every single time.