I installed the program on a windows 7 laptop and everything is working fine.
Seems to be a windows 10 problem.

<t>I did copy and paste the lines of code in a note-pad file.<br/>
Saved the file as an ini file since I copied and pasted the name you gave in the text.<br/>
Copied the ini file into c:/programfiles/sweethome 3D and than restarted the program.<br/>
unfortunately still the same result: the fonts are ...

I use Windows 10 and have exact the same problem. I made the text file but cannot find the ini file as is described?
What else can be done or how can the ini file be missing?

I am having the same problem with Windows 10.
Made the text file as suggested by Puybaret but I cannot find the ini file in the C:\programfiles\sweethome 3D file.
Any other suggestion?