Can you confirm what service pack you are running? You can do this by launching SolidWorks and going to Help > About SolidWorks.
You should note that only 2015 SP5 is supported on Windows 10. Earlier service packs exhibit the same issue you mentioned. You should upgrade to SP5 if you are using an earlier version. Or if your company policy prevents you from doing this at this time you should be able to get some stability back by setting SolidWorks to run in compatibility mode with Windows 7. (Right click the desktop icon > properties > Compatibility tab)
Hi Phil, what service pack of 2015 have you installed? Windows 10 is supported only for 2015 SP5.