I am trying to add new fonts to my Netbeans editor by downloading them and double-clicking the .ttf files and pressing \'Install\' on the upper left corner. I am able to ins
Initially I had the same problem as you. After installing the new fonts and rebooting, those new fonts were not available in NetBeans 10.0, even though they were available in other applications such as Firefox and Notepad.
In my case, installing the *.ttf files resulted in them being installed in a user specific folder: C:\Users\johndoe\AppData\Local\Microsoft\Windows\Fonts
.
However, after I copied (only) the *.ttf files for Inconsolata from that folder to C:\Windows\Fonts and rebooted again, the Inconsolata font was visible in NetBeans 10.0. Here is a screen shot showing the use of Inconsolata font:
Notes:
C:\Windows\Fonts
.C:\Windows\Fonts
in a special way. Instead, copy the *.ttf files to C:\Windows\Fonts
using copy from the command line: