Firefox now looks at Windows 7 text enlargement settings. For an alternative and more adjustable option. Do the following:
- Disable the settings in Firefox that track Windows Font Settings. Type about:config into the Firefox address bar. Change the value of layout.css.devPixelsPerPx from -1 to 1.
- Install No Squint.
- You can also adjust Firefox’s interface text by installing Theme Font & Size Changer.