You need to first check if the files are associated correctly.
Right click on any part -> Properties -> Choose default program. Select 'SolidWorks Launcher'. Ensure to tick check box, use this file for all 'sldprt' files. You have to repeat the procedure for assembly & drawing files as well. When done, check the right click menu in windows file explorer.
Now its working....
Previously I had Solidworks 2015 selected as the default programme.