hello, have you set windows to display elements at 100% in the windows control panel > appearance > display? more information about that is available at http://windows.microsoft.com/en-us/windows7/make-the-text-on-your-screen-larger-or-smaller

Give these a try and see if they help. Ctrl + increases the size Ctrl - decreases the size Ctrl 0 (zero) resets to the default

Reset the page zoom on pages that cause problems. *<b>View > Zoom > Reset</b> (Ctrl+0 (zero); Command+0 on Mac) *http://kb.mozillazine.org/Zoom_text_of_web_pages ---- You can set the layout.css.devPixelsPerPx pref on the <b>about:config</b> page to 1.0 or on Windows 8 to 1.25 and if necessary adjust layout.css.devPixelsPerPx starting from 1.0 in 0.1 or 0.05 steps (1.1 or 0.9) to make icons show correctly. *http://kb.mozillazine.org/about:config See also: *https://support.mozilla.org/kb/forum-response-Zoom-feature-on-Firefox-22 Use an extension to adjust the text size in the user interface and the page zoom in the browser window. You can look at this extension to adjust the font size for the user interface. *Theme Font & Size Changer: https://addons.mozilla.org/firefox/addon/theme-font-size-changer/ You can look at the Default FullZoom Level or NoScript extension if web pages need to be adjusted after changing layout.css.devPixelsPerPx. *Default FullZoom Level: https://addons.mozilla.org/firefox/addon/default-fullzoom-level/ *NoSquint: https://addons.mozilla.org/firefox/addon/nosquint/