As the customer bulletin, DS SOLIDWORKS announced the support of Windows 10 64-bit Pro in SOLIDWORKS 2015 and SOLIDWORKS 2016.
2015 SP 4 is available but not supported yet, so I'm assuming that it would be SP 5. Many users have mix results using 2014/15 on Windows 10. So in case you want to install/use SOLIDWORKS, I would suggest going with the latest release i.e. 2015 SP 4.