Reboot and try again.
What is the resolution of the monitor?
Does your laptop run at high DPI scaling in windows (4K resolution)?
This is a bug with 2016, it has been assigned SPR 937341 if you want to ask your reseller to add you to it. In SOLIDWORKS 2017 the RX dialog scales better, but is still not perfect. We're looking into a full fix.
Thanks for your comment.
The resolution is quite high 3840 x 2160. I tried reducing it and it helped. I will ask my reseller to add me to SPR 937341.
Thanks for your answer.
I did reboot and it didn't help.
The screen resolution is 3840 x 2160 (Wow ! I've never seen a resolution that high !)
And its probably the problem.