READ VERY CAREFULLY!!!

How to change Logon Screen

It's recommended to install Windows 7 Service Pack 1 before you change system files.
Also it's recommended to install fonts from folder "Windows 8~8.1 Extras\Fonts\Segoe UI" before you change logon screen.

FOR WINDOWS 7 32-BIT USERS

1.Take ownership (permission) of a file "authui.dll" from folder "C:\Windows\System32" and rename it to, for example, "authui_old.dll".

2.Copy "authui.dll" file from folder "Windows 8~8.1 Extras\Logon Screen\32-BIT" to "C:\Windows\System32" folder.

3.Also you must change logon screen background. To do this, download Logon Changer for Windows 7 from this address:
http://tweaks.com/software/tweakslogon/
and follow instructions from this site how to change logon screen background.

4.Choose "Logon.jpeg" file from folder "Windows 8~8.1 Extras\Logon Screen\Background".

5.Before you log off or reboot your computer, test logon screen with Ctrl+Alt+Delete.

FOR WINDOWS 7 64-BIT USERS

1.Take ownership (permission) of a file "authui.dll" from folders "C:\Windows\System32" and "C:\Windows\SysWOW64" and rename it to, for example, "authui_old.dll".

2.Copy "authui.dll" file from folder "Windows 8~8.1 Extras\Logon Screen\64-BIT" to "C:\Windows\System32" folder. Also copy "authui.dll" file from folder "Windows 8~8.1 Extras\Logon Screen\32-BIT" to "C:\Windows\SysWOW64" folder.

3.Also you must change logon screen background. To do this, download Logon Changer for Windows 7 from this address:
http://tweaks.com/software/tweakslogon/
and follow instructions from this site how to change logon screen background.

4.Choose "Logon.jpeg" file from folder "Windows 8~8.1 Extras\Logon Screen\Background".

5.Before you log off or reboot your computer, test logon screen with Ctrl+Alt+Delete.

How to take ownership (permission) of a file you can find on this address:
http://www.askvg.com/guide-how-to-take-ownership-permission-of-a-file-or-folder-manually-in-windows/
http://www.askvg.com/add-take-ownership-option-in-file-folder-context-menu-in-windows-vista/

All you are doing, doing at your own risk. For the possible consequences i am not responsible.

Tested and working on Windows 7 Service Pack 1 32-bit and 64-bit.