Welcome to Bleeping Computer, jstew_13
Have you tried to go into safe mode? If so, and if you can access the start menu, I would change your wallpaper back to what it was before you made this change. What wallpaper was this? Anyways, I copied out some instructions from the sources mentioned at the bottom of this post(modified a bit), that will walk you through going into safe mode and changing your wallpaper.
Hope this helps....How to start Windows in Safe Mode:
1.) Restart your computer.
2.) When the machine first starts again it will generally list some equipment that is installed in your machine, amount of memory, hard drives installed etc. At this point you should gently tap the F8 key repeatedly until you are presented with a menu.
3.) When you have the menu on the screen. Select the option for Safe Mode using the arrow keys.
4.) Then press enter on your keyboard to boot into Safe Mode.Changing the Desktop Pattern or Wallpaper:
1.) On the Start menu:
* Point to Settings.
* Click Control Panel.
2.) In Control Panel:
* Double-click the Display icon.
The Display Properties dialog box appears. The Background tab will be showing, and the Wallpaper list will be highlighted.
3.) Select the Wallpaper that best fits your needs.
* If you have wallpaper saved in another file:
* Click Browse.
* Type the file name.
* Click Open.
4.) To select how your wallpaper is displayed on your monitor:
* In the Display box select Center, Tile, or Stretch.
5.) Click OK.
6.) Restart your computer.
Sources -How to start Windows in Safe ModeChanging the Desktop Pattern or Wallpaper