Hello! My problem is that FF itself is not displaying/rendering fonts as it should or not at all. Weird part is that OS in questions is a fresh install, and it did not show itself at start, ie it worked normally, but later after few runs of FF it suddenly started (no apparent cause AFAIK), the only thing that could affected it is OS updates, which I am running ATM. Some clarifications/additional info: -Only FF is affected ( maybe Thunderbird too , did not install to check) EDIT: just did, TB is OK -Only FF PROGRAM FONTS are not displayed, and some ( ex: about:config ) in-window page content -After blindly finding option to change font/s, it did nothing -Cleaning/New/Deleting/Resetting/Restoring OLD Profile/Firefox does not help -Reinstalling FF and or Cleaning all registry entries related to FF does not help -HTML content works as it should (at least all I checked) -Windows 7 fresh install (currently doing win updates), with basics software installed and drivers (not much to mess up things) -I cannot edit anything in about:config due to it not being shown properly, and I do not know of any .cfg/.ini/etc file to try I don't know what else could help You troubleshoot, but will add whatever needed I'm including some screenshots to help you understand: http://i.imgur.com/kSq0sCY.png about:config page http://i.imgur.com/Oj1PCxY.png http://i.imgur.com/YwcBUgt.gif http://i.imgur.com/fcfOA1Q.png http://i.imgur.com/wkxbeLC.png http://i.imgur.com/WTI8H3u.png