"Always show icons, never thumbnails" checkbox in Folder Options is OFF.
I've tried emptying the thumbnails' cache folder (via Disk Cleanup and manually).
Visual Effects (Performance Options) are set to best appearance.
The View settings in Explorer are set to Large Icons, but this is irrelevant since the thumbnails do the same thing regardless of any settings.
When I hit F5, occasionaly some of the thumbnails reappear for a second, then disappear again, being replaced by the default icons.
nothing has worked
