If you're newbie, the questions answered there will help you understand what's with all the fuss around codecs and of course, exempt us from answering already answered questions
Here is a question that, i bet, many multimedia savvy guys don't know the answer:
How do I tell which codecs are installed on my computer?
If you need to see a list of the Windows Media Player components and codecs installed on your computer, do the following:
1. On the Help menu, click About Windows Media Player.
If the Help menu is not visible, click Organize, point to Layout, and then select Show menu bar.
2. On the About Windows Media Player dialog box, click Technical Support Information.
Yes, it's that simple! No codec identifiers, viewers or other tools.
If this FAQ doesn't shed some light on your questions regarding codecs, i also suggest you to check:
What do you need to know about codecs and, of course, the famous question (and guide)... What Codecs Should I Use?
Other good articles about codecs:
All About Video Codecs and Containers - from Tech Hive:
http://www.techhive.com/article/213612/all_about_video_codecs_and_containers.html
What Exactly Is 'Codec'? Why Would I Ever Need It? - from about:
http://netforbeginners.about.com/od/multimedia/f/codec.htm
Good luck and welcome to our new forum!
Later edit:
Windows DVD Maker FAQ is here:
http://windows.microsoft.com/en-us/windows-xp/help/movie-maker/faq#T1=tab01
and Common Movie Maker errors, here:
<a href="http://windows.microsoft.com/is-is/wind ... ors-faq</a>
the List of Multimedia Fomats Supported by Windows Media Player:
http://support.microsoft.com/kb/316992