Does the black border appear all the way around the wallpaper (but not underneath the taskbar), with the image in the center?
If so, it may be that you simply need to change the way that windows displays the wallpaper.
To do this:
- Right-click on the desktop and choose "Personalize" from the menu that appears.
- Click on "Desktop Background".
- Select the desired background.
- At the bottom of the window, right above the "ok" button, there will be several sizing options. You probably want the first one, which is "Fit to Screen" (place your cursor over each option to see an information balloon describing it). This will stretch out your wallpaper to fill the desktop. Click on the sizing option that you desire.
- Click "ok" to apply the changes.
If, on the other hand, the black border appears around the wallpaper and also below the taskbar, then it is most likely a resolution or driver problem. In this case, Marilyn's suggestions above will hopefully help you resolve the problem.
Best Wishes,
BookwormDragon