I don't know the exact font, but here is an AWESOME website with tons of fonts with @fontface kits you can download for your website: Handpicked free fonts for graphic designers with commercial-use licenses. | Font Squirrel

The exact font is 'Tahoma'

Google: what the font. Click the link and you can upload an image and it will tell you what don't it is. That writing might be a little small though.

i think it's tahoma