Change Windows 7 Logon Screen with Windows 7 Account Screen Editor
Windows 7 Account Screen Editor is a freeware windows utility developed by Deviantart user, which allows you to customize the logon screen background of Windows 7 very quickly and easily. All you need to do is to click on Set background button and choose a picture for your logon screen background.
Whenever the picture you selected for background is large, ASE will automatically make the picture smaller.
If you want to switch back to default logon then click on Default background button to change the logon screen background to the default background.