Satellite A200 does not play DVDs won't play

Question

I'm a first time user on this forum so hello to everyone.
My problem is that my (Vista-running) A200 Satellite will not play DVDs. When I try I get the following message: "Windows Media Player cannot play DVD video. You might need to adjust your Windows display settings. Open display settings in Control Panel, and then try lowering your screen resolution and color quality settings. Needless to say, I've played around with the relevant settings and there was no change to the situation. In a response posted at a different forum, someone suggested that I ditch Windows Media Player in favour of something better. I thought the alternative program he suggested would be free but it wasn't. Anyway, I've tried playing DVDs with other programs and got the same basic message. So it's not a Windows Media Player thing, it's a playing DVDs thing. Also, it doesn't matter if WMP isn't the BEST DVD player - I just want to play DVDs!! I've written to a Microsoft customer care helper person and they wrote back saying that it wasn't their problem. They consider it a "hardware matter". I don't buy that.
Just some history - I bought the computer second hand from a good friend. Now I can't remember ever playing a DVD on the computer, which slightly confuses things for the following reasons. Just after I bought the computer, which runs Vista, I installed MP3 player software that disagreed with the CD/DVD player drivers. This I think is a fairly common problem. That time Microsoft reps were happy to help me and told me to delete two key lines of the registry. That fixed the problem to some extent because now the drive a) existed again and b) could read and play CDs. But when I tried to play a DVD I got the above-mentioned message.
So like I say, as I don't remember ever even trying to play a DVD on the drive, I don't know whether or not the problems are related to the MP3 software clash problem, although it doesn't seem unlikely that they are related. Finally, the computer was less than a year old when I bought it and in every other respect it has been fine (Vista's intolerable sluggishness notwithstanding). Sadly the extended warranty has now run out so I hope it's not a hardware problem. The point is that since I've never even played a DVD on this thing, and it plays CDs with no problems (furthermore, the drive can READ DVDs, it can tell me all the chapters that are on a DVD and read files off it - it just won't play movies), I don't think it's hardware. I think there's some bug going on.
If anyone could shed any light on this matter, I would be eternally grateful!
Regards
Tom

Answer 1

Turns out that my confidence in Windows Media Player was misguided.
I wrote and said as much to the Microsoft rep who advised me to look elsewhere for advice.
I further told him that from now on, if I meet anyone with the same problem I will give them the advice with which I was originally provided - don't use Windows Media Player.
Heeding the rep's advice, I looked around on the website for the company that produced my DVD drive (Mat****a DVD-RAM UJ-850S ATA Device) and in other forums, I forget where I found the advice but this media player:
Videolan Media Player Downloadable for free at:
http://www.videolan.org/
seems to play DVDs with no problems. I hope someone else might benefit from the information.
Good luck to all