Using notepad, try the following change in Win.ini to globally replace the MS Sans Serif font in Ultimate Family Tree displays, including the Fan Chart. Reboot as required. This should not affect any report printouts, in UFT. Other programs???
[FontSubstitutes] New Font=MS Sans Serif
To turn it off, put a semi-colon at the beginning of the line or carefully delete it. Reboot.
Good Luck, but Standard non-respnsibility disclaimer applies.
You may have to go into Windows Control Panel/Display to recover if Windows resizes certain fonts, so make a note of each listed font setting in Display before you start.