Thank you for the version number.
In the reply window (not a comment window) there is a button about 5/6 of the way across, which is for an image (a mouseover will reveal "Image"). It has to be a linked URL image, so at least as far as I can tell, you'd have to upload it somewhere, copy the URL once uploaded, then paste that URL into the field after clicking the Image button.
I should have asked which Windows version, although since you said "new" I would guess it to be 10. I can only work in Windows 7; the Display control panel is where I'm going, and I have it set to "Smaller - 100% (default)". I believe that is required to operate CDE products (I could be misinformed here, but I haven't changed mine) so I also suggest checking that.
Always check, download, and install the most recent update of your software to ensure that issues may have been corrected.