This is a good idea – i was thinking of a way to see how the logon studio (doesnt) works ill check it out!
edit: it will take some time to investigate the whole login process and eventually compare it between vista and 2008.
Just as i suspected all logon studio do is to change the imageres.dll file and thats not enough for 2008, because looks like it doesnt even load the background from there.
In the meantime if anyone is interested, here are the process monitor logs from vista and 2008.Test conditions:
All possible processes and services stopped, started logging right before executing the switch user command, stopped logging after the completing of the operation.All other OS settings are unchanged.
It is possible that the settings or files responsible for the change of the login background image may be loaded at other time – at boot for example, but logon studio uses the switch user command to show the changes so im assuming that the actions required to change the login screen background are loaded at that point too.
btw the background color used in the login screen is “29 95 122”