The HP w2408 doesn't have a DVI port. It has a VGA and a HDMI (+audio for the 2 built in speakers).
I wasn't very happy with this, as my slimline didn't come with a DVI port. (and I had upgraded the graphics card to one without HDMI, too).
However, looking at HP computers of that time (early to mid 2008), it makes total sense, as none of their computers had DVI only. They would mostly be VGA or HDMI (on the then popular 8500GT card) models.