thanks for the reply.
I tried to adjust the clear type but that didnt solve my problem
I did some tests with an html with some text and changing the font family.
The problem comes when I set the font-family to "Arial,Sans-Serif", if I change the font family to "Verdana" it displays the font correctly.
IE9 is not missing the font but rendering it differently I don't know why, I uninstalled and tried with IE8 and no problems :S