Hello all! I am new at Inkscape too, and were facing the same issue after re-installing Windows 10 (pro, 64bits, build 1809) my font (KG drops of jupiter) and Inkscape 0.92. The font was listed on Windows fonts, but not in Inkscape....... So, after reading this post, tried to right click on font file, and choose "install for all users" - instead of only my user is created. Opened Inkscape and.... surprise! KG Drops of Jupiter is now listed! Great!