How can I connect my Xbox 360 to my computer to use shared files?

I have movies on my computer in a shared directory and I would like to stream them via my x360 so I can view on my tv, and I know the x360 can convert just about any video format into viewable content for TV.

I had tried to do this a couple years ago but was advised I had to use a Windows Media box in order for the 360 to link up to shared folders. I find this very hard to believe. However when then x360 would search for the targeted shared folder on my computer I would receive a message folder could not be found, verify this is a shared folder.

So I was hoping something has changed by now. I did verify my network connectivity and that is working correctly.

My computer is using XP Pro