Vista does not support WMP 10.
It would help if you tell us what you don't like about WMP 11.
I use XP. I currently have installed.
DivX: Not compatible with Vista
http://www.divx.com/
Used to play AVI/ DIVX files in WMP, RealPlayer etc.
An alternative is the Xvid codec or "ffdshow-tryouts"
"ffdshow tryouts"
http://ffdshow-tryout.sourceforge.net/
Xvid 1.1.3
Windows 95/98/Me/NT/2000/XP/2003 Server/Vista
http://www.download.com/XviD-Video-Codec/3000-2140_4-10651549.html?tag=lst-0-2
http://www.xvid.org/
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ITunes 7.5/Quicktime : XP/Visa
http://www.apple.com/itunes/download/
Realplayer: XP/Vista
http://realplayer.com/
Winamp 5.5: Not compatible with Vista
http://www.winamp.com/
Windows Media Player 11
VLC Media Player 0.8.6c
Windows 95/98/Me/NT/2000/XP/Vista
http://www.download.com/VLC-Media-Player/3000-13632_4-10717934.html?tag=lst-0-1
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Notes:
RealPlayer Free Version has a built in movie downloader (including YouTube videos). Once installed, users will see a "download this video" button hover next to video when the mouse cursor is over the video on thousands of Web sites.
Also plays FLV (YouTube) videos.
VLC Media Player 0.8.6c
From VideoLAN Project:
http://www.videolan.org
VLC (initially VideoLAN Client) is a highly portable multimedia player for various audio and video formats, including MPEG-1, MPEG-2, MPEG-4, DivX, MP3, and OGG, as well as for DVDs, VCDs, and various streaming protocols. It also can be used as a server for unicast or multicast streams in IPv4 or IPv6 on a high-bandwidth network.
The most prominent additions to version 0.8.6 are probably Windows Media Video 9 and Flash Video. Other important changes are improved H.264 decoding, better Windows Unicode support, and a full-screen controller
Version 0.8.6c includes cropping in Direct3D and a variety of bug fixes
In addition to playing most video files, it also plays MPEG-2 files that often require a purchased decoder, as well as most other formats including AVI, VOB Files and FLV file
ffdshow tryout
http://ffdshow-tryout.sourceforge.net/
ffdshow-tryouts is the updated version of ffdshow.
(ffdshow has not been updated since 2006 and does not support Vista)
Play all your favorite videos with just one download! Be it Xvid or H.264, FLV1 or MPEG2, ffdshow tryouts supports a wide range of video codecs. On the audio front, ffdshow tryouts impresses with support for popular codecs like MP3, AAC, Vorbis, AC3, and DTS as well as not-so-popular ones like LPCM, True Audio, and QDM2.
A powerful filter set further helps you to improve your audio-visual experience: filters like denoise, deblock, and resize enhance the quality of your videos. Normalization, down-/upmixing, and resampling - to name a few - try to get the most out of your audio setup.