I assume no responsibility for anything that can go wrong going wrong while attempting to execute the instructions in this post. Do this at your own risk.
Place your images in \Windows
Go to: HKCU\Software\Microsoft\Today\Taskbar\TaskBarTheme Image
Change the path to: \Windows\hdwall_taskbar.png
Go to: HKCU\Software\Microsoft\Today\SoftKeyBar\SoftKeyBa rThemeImage
Change the path to: \Windows\HDwall_softtkeybar.png