Disable the Thumbnail Cache

Start/Run/Regedit
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ Explorer\Advanced. Value Name: DisableThumbnailCache, Data Type: REG_DWORD (DWORD Value), Value Data: (0 = enabled, 1 = disable cache). Create a new DWORD value, or modify the existing value, called 'DisableThumbnailCache' and edit the value according to the settings below. Exit your registry, you may need to restart or log out of Windows for the change to take effect.