Second try : Rename the file IconCache.db located in C:Documents and SettingsUser NameLocal SettingsApplication Data and reboot.

Follow the instructions below to change the external display settings. First try: Right-click on the desktop, choose Personalize, then Change desktop icons, and then click on Restore Default, then logout & login (or reboot). Windows uses the term Duplicate instead of Mirroring. To turn on (or off) Desktop Mirror click the small icon of a monitor on the upper right side of the menu bar and select Turn On Mirroring Changing the Desktop Mirroring Setting Windows – Change External Display Mode In Extend Mode the external display is treated as a separate screen so that you can have a different windows open on the projector and desktop. It is easy to switch between the two settings. Right-click on the desktop and select New > Folder from the popup menu. You can add a shortcut to the desktop so you can quickly access the classic Personalization window if you prefer it. In Mirror Mode the computer monitor duplicates the monitor on the external display so that you see the same picture on both the desktop and projector. However, the Personalization window from Windows 7 is still available in the Control Panel. When connected to an external display, Mac and Windows computers have two different display modes: Mirror and Extend.

Windows 7 desktop