I've found a hidden login wallpaper in Windows 7, and it happens to be in imageres.dll. Here's how to get it. 1. Download Resource Hacker. 2. Locate imageres.dll in your Windows folder. (Should be in System32.) 3. Open imageres.dll with Resource Hacker. 4. Open the "IMAGE" folder. 5. Look inside folder numbers 5044-5056. 6. Have fun.