Preferred Filter Tweaker lets you use third party filters in Windows 7

Windows 7 uses its own DirectShow filters for decoding audio and video formats. You can’t use third party filters without making changes to the Registry.
Preferred Filter Tweaker for Windows 7 is a freeware tool that lets you use third party filters like ffdshow, CoreAVC, DivX , Cyberlink, etc with just a few mouse clicks. And of course the changes can be always undone.

For example, if you prefer to use ffdshow or CoreAVC for decoding H.264 video then you can do so by using this tool.
Currently supported third party filters (32-bit):
• ffdshow
• MPCVideoDec
• CoreAVC H.264 decoder
• Xvid MPEG-4 decoder
• DivX H.264 decoder
• DivX MPEG-4 decoder
• DScaler5 MPEG-2 decoder
• Gabest MPEG-2 decoder
• Cyberlink H.264 decoder (PDVD 7/9)
• Cyberlink MPEG-2 decoder (PDVD 7/8/9)
• Cyberlink VC-1 decoder (patched with VC1Tweak: guid {394DFD1B-6F4C-4096-AA14-EF852B02595B})
• ArcSoft H.264 decoder
• ArcSoft MPEG-4 decoder
• ArcSoft MPEG-2 decoder
• ArcSoft VC-1 decoder (patched with VC1Tweak: guid {9DAD7B50-4432-4F48-AC60-B2B4E854454B})
• MONOGRAM AAC decoder
Currently supported third party filters (64-bit):
• ffdshow
• MPCVideoDec
• Xvid MPEG-4 decoder
• Gabest MPEG-2 decoder
More information and download.