how to change logon wallpaper in windows 7 without using software or tools hacks

1. Download the registry file from here. Extract the file and double-click on the file to enable this feature (Alternative method: right-click, select Merge).

2. Now, head over to the following folder:

C:\Windows\System32\oobe (“C” is your Windows Seven Installation drive)

3. Here, create a new folder named Info. Again, create a new folder inside the Infofolder and rename it as backgrounds.

4. Copy your favorite image file to this folder and rename it as backgroundDefault. Note that the image must be in JPG format and the size should be less than 256 KB.

5. You are done. Reboot your system and see the change.