I had the same problem and this is the solution my VAR sent me.
Control Panel\ Appearance and
Personalization\ Display\ select “Let me choose one scaling level for all my
displays”\ select “Custom sizing options” \ set the “Scale to this percentage
of normal size” setting either to a value less than 171% or a value greater
than 183%\ select OK\ select Apply\ Sign out of the machine \ Sign back into
the machine. Retest.
This issue was fixed in SW2016 SP3. The "early visibility" of SP3 is currently available and the full, public release of SP3 is slated for mid-April.
I have a laptop with 4k display and I have 2017 version of Solidworks but unfortunately the texts and icons are again tiny , I use windows 10, I have a 15.6 inch screen and the resolution is set to 3840x2160 all of the icons and texts in windows are correct but in some apps I have this problem.My text size is at 250% .
The first picture is SOLIDWORKS with correct scaling that I did with trick of Dan Antoneilli (it doesn't solve the problem completely for this software, it cause other problems during working) and second picture is the original scaling in my screen
I guess that's price you pay for being on the bleeding edge of the hardware . Kind of ironic how one of the reasons for the icon changes in 2016 was to address 4K displays.