Installing Blender on windows 10 pro reduces UI size I have been using Blender for few years on Linux Ubuntu on my Thinkpad and I never faced problem in Blender installation and running smoothly even in my 2 GB ram Linux laptop.
Recently, I tried to install blender latest version 2.79 from blender.org in my new Dell xps 15 16 GB ram with Windows 10 pro. I am facing terrible lagging problems,

If I install old version like 2.77 or 2.78 or 2.76 there is problem like I cannot see the tabs anymore. They are so small that I cannot see them.

I cannot understand where is exactly the problem. I have all the pythons installed properly.
Can anybody tell me the solution. Is it problem with blender and windows 10 compatibility?
I have attached the screen shot,  please have a look and tell me the solution.
It's looks like you have retina display, that means it has four real pixels in one digital pixel.

Open File > User Preferences

or CTRL+ALT+U

And the very first entry at the top:
Display: Scale

Set it to 2.