Kindly I ask your attention.
Well, I use Windows Media Player 12 and VLC Player x64.
Standard it's set to WMP and files that can't be opened, by VLC Player.
Why WMP11?
Windows XP?
Actually, it doesn't matter. When you download a decent Codec Pack, Windows will give the best quallity and VLC Player will play most of the files.
Decent codec packs:
K-Lite, Shark, Windows Codec Pack, VLC Codecs and so on.
They are all free to use, so.
What you could do is the next:
Start your browser and type:
List of best free codec packs
When using x64, might be that you need to install x32 too. When not mentioned on there website, just install the x64.
You will find a lot of links to go for.
Hopefully I let you known enough, that you will find the answers you seek!
Good luck and have fun doing it!
Best Regards,
MeneerWitte