Adjust font size in the Firefox menu(Firefox)

                   You need to increase the size of the text in Firefox's menu and tool bars, and the Windows controls aren't enough.

                 You can increase the font size of the fi le menu items and reduce the font size of the bookmarks if you find  it  to  be  too  large. Firefox  uses  the Windows default settings, so you could increase the DPI value of the system font size. Alternatively, you can customize the required settings by creating a 'userChrome.css' file instead. You can find the sample file at ‘C:\Documents and Settings\\Application Data\
Mozilla\Firefox\Profiles\j53h8g9g.default\chrome'. For example, to set the font size to 20 px for all elements of the Firefox interface, add the line '* {font-size: 20pt !important}'.You can also edit individual elements, but for that, you will have to locate the correct CSS selectors. For more samples of CSS codes, visit http://
www.mozilla.org/unix/customizing.html