Few days back i installed new fonts because i am a graphics designer so i did what i was suppose to do but after that everything on firefox messed up. first of all i noticed it on fiverr as i am a freelancer so i use fiverr as my workplace all the time so all the fonts became bold and italic. then after few days i came to firefox addons page and found the same issue on that page. Check the screenshot http://awesomescreenshot.com/0ee3zczqff as you can see menu and all other fonts messed up. Same thing happened at firefox site http://awesomescreenshot.com/05c3zczr58 i have tried re-installing Windows 8 default fonts. I have tried re-installing firefox. i have tried reset windows fonts settings to default. i have tried firefox Options>Content> Font settings in firefox. I tried one more thing which is in firefox fonts settings when unchecked use website default fonts instead on my selected fonts in firefox options. all websites started with which i am having this issue started using fonts i selected in firefox options. when i checked back that checkbox and refresh the page it came back to the same condition. Please help me to fix this issue. Thank you in advance.