There is a program called Settings Locked...you can find it here:
Code:
http://mechodownload.com/forum/showthread.php?t=35534&highlight=lock+wallpaper
Another way...
First set the wallpaper exactly how you want it.
Start > Run > Type "regedit" > Run.
Navigate to HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ ActiveDesktop.
Right-click in right pane and select New DWORD Value.
Name this new DWORD NoChangingWallpaper and set the value to be 1.
Reboot your computer. The wallpaper option should be disabled. To re-enable it, set the DWORD value to be 0 or delete the DWORD altogether (don't forget to reboot).
If you have XP Pro:
Go to Start --> Run and type "gpedit.msc" without quotes. In Group Policy Editor, go to
Local Computer Policy --> User Configuration --> Administrative Templates --> Control Panel --> Display
There you have the setting with name "Prevent Changing Wallpaper". Enable this setting to do what you desire.
it doesn't matter which one you use though...I'm just giving you some options