Do you ever find your SOLIDWORKS thumbnails looking less like the part preview and more like the part icon?
The process used to generate thumbnails runs outside of the SOLIDWORKS process. It is called sldshellextserver.exe. This process will run when browsing Windows Explorer files, and there is an option to show thumbnails in Windows Explorer enabled within SOLIDWORKS. If the SwDocumentMgr.dll is not registered on the computer, the dll will not load within this process and thumbnails will not generate.
Make sure this dll is registered, then close and reopen Windows Explorer and see if the thumbnails now generate.
How to register SwDocumentMgr.dll?
Run the following from command prompt window or run command.
regsvr32 "C:\Program Files\Common Files\SolidWorks Shared\SwDocumentMgr.dll”
Hope this helps!
By: Sam Hochberg, Applications Engineer