Hi Isabelle..Thanks for replying. I've kind of been down his route before. The one you mentioned from Software Patch is actually for WMP 10, and I have WMP 11. I actually have an MPEG-2 decoder from Elecard (it's a paid version), but I'm waiting to hear from them to find out if it will work on Vista x64.

I also downloaded a free Cineplayer MPEG-2 decoder from Softpedia:
Download Stinky's MPEG-2 Codec 1.2.0.79 - Stinky's MPEG-2 Codec will allow you to open MPEG-2 files in TMPGEnc and in MS Media Player, plus a host of other programs - Softpedia, but it's the same thing there, the file is dated from 2003, so I don't know if it will work on Vista x64.

I did download another one from Softpedia, I think it's actually the same one and tested it. After I installed it, I could play DVD's but I couldn't get any sound! After that, I did a little research and discovered I may need something called an AC3 Filter: AC3Filter

There's also MPEG-2 decoders that you can buy from a Microsoft add-on page that I saw but now can't find! But I found out hat if you put in a DVD into your player and open it up in WMP, you will get a messsge that WMP cannot play this file and it will list a link where you can buy those codecs I mentioned.

But I'm not going to go that route unless I can help it. I know there had to be a free way to do this somehow. One of these days, I'll get all of this sorted out.