When you try to change the desktop wallpaper in a Microsoft Windows XP-based computer, the options may be missing or unavailable. Therefore, you cannot change your wallpaper or use other options that are located in the Display Properties dialog box. This problem may occur after you remove spyware from the system.
This problem occurs when a registry key is set to hide or to lock the display settings on the computer. The registry key can be set by an administration policy or by malicious software.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
To resolve this problem, follow these steps:
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey: