I wanted to change the login screen for Windows 7 and Vista. I know I had a program on Vista that allowed me to change it without a problem, but I can’t seem to find it after I wiped out the drive :).

So anyway, here’s another free way to change it without going into the registry yourself:
http://it.thelibrarie.com/utilities/W7C%20LogonUI%20Changer.exe

Open it up, click on the middle, select your picture, and away you go. It resizes and everything. Yay.

Or for the jerks out there that want to remotely have fun with coworkers:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background

Check to see if a DWord value named OEMBackground exists and has a value of 1. If not, right click the white-space and create a DWORD Value for this.

Put an UNDER 256KB file in this directory:
%windir%\system32\oobe\info\backgrounds
Name the file backgroundDefault.jpg