The thumbnail graphics are simply icons cached with the file and displayed in Windows Explorer by Microsoft. Microsoft decides when to update the cached icon information, and therefore when to change the display of the icons. In this case, it may be that access to the file is needed to get the icons to update. For example, selecting the file in Windows Explorer or opening and saving the file usually fixes the problem. Sometimes the registry location where the icon information is cached becomes corrupted. We do not know the cause of this problem. To see if this is the case, run the "regedit" command, and then expand HKEY_CLASSES_ROOT. Under HKEY_CLASSES_ROOT, there must be a SldAssem.Document folder and an SLDPart.Document folder. Each folder must have a "shellex\iconhandler" folder. If the "shellex" or "iconhandler" folder is missing, the thumbnail graphics will not function. A reboot will often be required to see the changes. |