On the 3.9 CD itself.
In:
OS-Version3.9/Extras/Backdrops/1024X768/Coming Soon.jpg
or
OS-Version3.9/Extras/Backdrops/1024X768/Get It.jpg
They have a small "Coming Soon" / "I'll Get It" on them which can easily be removed with a paint program. The "I'll Get It" one will be easier to remove as it interferes less with the graphics.
Also, it would be a good idea to rename the file without the space when you copy it to Hard Drive.
Cheers