/me sighs
You can't fix this by "downloading a font"
The problem is simple, your driver isn't able to render the font textures correctly. The only fix is to update your driver.
Since it's only ancient decrepit drivers or ones that Microsoft provide that cause it, I somehow doubt that you actually looked for a newer one.
If you need help hunting for a driver then say what graphics hardware you have, and someone will point you in the right direction.