How To change Windows 7 Logon Screen:
Bored using same Logon Screen. Here it show's how to change windows 7 Logon screen.
Just follow these simple steps:
1) Open "START MENU" and write "regedit" into search bar, press enter.
2) Rgistry Editor will open. Find "HKEY_LOCAL_MACHINE". Right-Click on it and select "Find".
3) Search bar opens, enter "OEMBackground". It should be here. ( Registry will automatically go to that path.)
"Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background"
NOTE: If the key does not exist, add a new DWORD value with the name OEMBackground.
4) Double Click on "OEMBackground". Menu opens. Change the value from 0 to 1.
5) Now go to "My Computer" and paste the following code in the address bar.
%windir%\system32\oobe.
6) Now create a new folder "info" if not present. ( IF present then skip this step)
7) Inside "info" folder create another folder name "backgrounds".

Now just paste the picture you want to put at Logon screen.
9) Rename the picture to "backgrounddefault.jpg" and place it inside the "backgrounds" folder.
Its done. Now to check switch user to see the effect.
Important: The image size should has to be less than 245Kb in size.