How to Change Windows 7 Logon Screen (Without Tools)

Step-01- Open regedit, and create the key -HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background

Step-02- Right click on the right hand side and then add a new DWORD Value named OEMBackground

Step-03- Double click on OEMBackground and set it to 1.

Step-04- Put the image file (in ‘jpeg’ format) in the following folder (You may need to create some of these folders along the path)

%windir%\oobe\info\backgrounds

The file must be named backgroundDefault.jpg and make sure that the file size is less than 256KB.

Step-05- Reboot your computer to view the changes in effect.

The following files (sorted by width-to-height ratio) are supported in %windir%\oobe\info\backgrounds folder:

1. backgroundDefault.jpg
2. background768×1280.jpg  (0.6)
3. background900×1440.jpg  (0.625)
4. background960×1280.jpg  (0.75)
5. background1024×1280.jpg (0.8)
6. background1280×1024.jpg (1.25)
7. background1024×768.jpg  (1.33-)
8. background1280×960.jpg  (1.33-)
9. background1600×1200.jpg (1.33-)
10. background1440×900.jpg  (1.6)
11. background1920×1200.jpg (1.6)
12. background1280×768.jpg  (1.66-)
13. background1360×768.jpg  (1.770833-)