This is common knowledge, yet strangely every time I rebuild my work PC (which is too often! Gah!) I try and Google the location of Registry keys and folders and always, always get a bum-steer. So here, have another (bum-steer?) version of this hack on the Net.

• Registry key to hack: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\ CurrentVersion\Authentication\LogonUI\ Background (you can stick this in a .reg file and Import from regedit.exe):

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background] "OEMBackground"=dword:00000001

• Directory to place your background image:

C:\Windows\System32\oobe\info\backgrounds

Call the image "backgroundDefault.jpg"

• The image must be JPEG format, and total size < 256KiB
• You can test straight away with Ctl+Alt+Del -- no need to reboot or logoff.