i've also had the same problem from the very beginning of pgAdmin4. The text looks like in your screenshot http://www.postgresql-archive.org/attachment/5988298/0/2017-10-16%2014_10_34-pgAdmin%204.png and this rendered pgAdmin4 unusable for me. And i also experienced the problems only with pgAdmin4. All the other Applications looked fine. No RDP was involved - i tested locally on the machine.
System: Windows 7 x64 Resolution: 1920x1080 GPU: Intel(R) G45/G43 Express Chipset Color-Depth: 16 bit ClearType: off
After hours of searching the web and trials and errors i finally found a solution for this problem. In my case the 16 bit color depth was the problem. Setting the color depth to 32 bit (and restarting pgAdmin4) resulted the fonts being readable.
@pgAdmin devs: Please make pgAdmin4 always render readable fonts - also in 16 bit color depth. THX.