I was having issues viewing part, assembly and drawing previews in Windows 7 File Explorer on "Details" mode. I sourced the forums and asked my reseller technical support, but no one could find an answer for me. I have Solidworks 2017 SP 4.1.
I have already tried these solutions:
1) Options --> General --> Show thumbnail graphics in Windows Explorer;
2) All solutions explained here: https://www.javelin-tech.com/blog/2016/03/solidworks-thumbnail-preview-missing/ EXCEPT for DLL registration.
I don't want to try DLL registration.
See attached file to see how thubnails look like now (Windows 7 File Explorer on "Details" mode).