1. In File Explorer, Right Mouse Button (RMB) Click on a SolidWorks part file and select “Choose default program”.
2. Assuming you have SolidWorks 201X installed, you will see a pop up window asking “How do you want to open this type of file (.sldprt)?” and the option of either ‘SolidWorks 201X’ or ‘SolidWorks Launcher’.
3. Make sure you tick the box titled “use this application for all .sldprt files”.
4. Select SolidWorks Launcher.
SolidWorks will then launch as normal. If you quit SolidWorks and go back to your part file in File Explorer, you will hopefully now see the familiar SolidWorks sub section of the pop up menu with Pack and Go, Rename, Replace and Move.
Please note that you will need to do this for all SolidWorks files – assemblies and drawings for example.
If not, try a repair install of your SOLIDWORKS