Anyone who handles 3D printers is not able to avoid the *.stl file format.
With the 3D-Builder Microsoft has released its own software wich handles *.stl files. This software is quite simple, but is sufficient for some tasks, e.g. scaling and merging models. Unfortunately Microsoft did not make the logical step and provides thumbnails for Windows. As you know well with pictures, it makes it much easier to find the right file, especially if you work with a lot of files.
Glad there is a tool called Marlin3DprinterTool, which is able to display thumbnails for Windows.
Actually, Marlin is an open source firmware for several 3D printers, but we only need one additional function that can be selected during installation.
After downloading the installation file from the Website, we run the *.msi file and click through the installation. At "Custom Setup" we remove the "Marlin3DprinterTool" from the list, so only the "FileExplorer STL Thumbnail Extension" is installed. Then we press "Install".
Caution: Administration rights are required.
Afterwards you have to register the preview images in the Windows registry, so that they are displayed in the File Explorer. Open the *.exe file "Marlin3DprinterToolStlConfiguration.exe", located in the previously selected installation folder, by default this is: "C:\Program Files (x86)\Marlin3DprinterTool".
After that opens (Caution: also here you need administration rights) a small window appears. There you click on "Install and Register STL Thumbnail". A small window appears with "Registration done with RegisterExtension" or "Register done with Shell Register".
Now we open a folder in the Explorer where the *.stl files are located and these are displayed with a preview image of the model. If you want to know where the following files come from, check out this series.
If you have any questions about marlin, *.stl files or 3D printers in general, just write it in the comments.