I have magnified images on home page and web sites
I had a new graphics card installed and when I clicked on the home page and the website was magnified and I have to use the scroll bar at the bottom of the page to get it all on the screen. Also happens on my e-mail account of thunderbird but not on any of my programs on my computer
ప్రత్యుత్తరాలన్నీ (1)
Did you check the Compatibility tab of the desktop shortcut to make sure that you do not start Firefox in a lower resolution?
See http://kb.mozillazine.org/Screen_resolution_changes_when_launching_application
Reset the page zoom on pages that cause problems: View > Zoom > Reset (Ctrl+0 (zero); Cmd+0 on Mac)