Sony PCG-F420 - Manual (Page 39)

Using the DVD-ROM/CD-ROM '
3
Remove the check from “Set to display 256 colors when playing back
a DVD.”
4
Click OK to confirm the setting.
To display wallpaper while playing a DVD (For PCG-F480 only)
1
Follow the instructions in “To play DVDs in Normal Display Mode
(For PCG-F420/PCG-F480)” on page 28, or
2
Follow step 1 and step 2 of “To play DVDs in Normal Display Mode
(For PCG-F420/PCG-F480)” on page 28, then remove the check from
the check box labeled “Do not show wallpaper when playing back
DVD.”