Problem with fonts on Windows 7

I have a problem with websites being loaded in a Bold font instead of the normal fonts,

for example this is how The Verge looks for me

Mtnso_medium

via i.imgur.com

It's been like this over a month, but it started happening with The Verge yesterday after a restart.

Help me, i'm out of clues, i searched the internet for solutions but all i found was solutions for Windows Vista that didn't help me at all,