Blu-Ray on Windows XP?

I have an HP Pavilion laptop. It came with Vista Premium when I got it in June, but I downgraded it to XP Professional (SP3). All drivers are installed okay now, but my Blu-Ray/CD/DVD drive is being weird.

I can’t play Blu-Ray discs OR files on my computer at all. I’m using Nero 8 with HD support. I tried downloading UDF 2.5 drivers and they installed okay, but it didn’t help the Blu-Ray problem. Please help!!!