Change Windows 7 default logon screen background

When you change your desktop background in Windows 7, it does not change the background for the logon screen. Since I have multiple machines connected to a KVM on my setup, I like to have different colors to signify which machine I'm actually looking at.

Windows 7 doesn't provide a good mechanism through the UI for changing this. To do it, you need to change a registry key and store your background as the correct file.

I found this post which was helpful: http://www.kodyaz.com/articles/change-windows-7-logon-screen-background-using-registry-oobe.aspx

Bascially,

1. Navigate to this registry key path with regedit.exe: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\
   Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background
2. Make sure the OEMBackground DWORD key is set to 1.
3. Navigate to C:\Windows\System32\oobe\info\backgrounds directory
4. There will probably already be a bunch of backgrounds there. Pick the one you want and save it as 'backgrounddefault.jpg'

That's it. You're done. Hit Windows-L to lock your screen and you should see the new background file.