for fun: use beautiful google datacenter pictures as windows 7 login screen image

The process is quite simple but I like this little utility much more:

http://www.julien-manici.com/windows_7_logon_background_changer/



I even did not have to reboot to check out if it works, just used WIN+L and boom there it was

links:
http://www.intowindows.com/how-to-change-windows-7-logon-screen-easily-without-using-hacks-tools/