I have the same problem describe here :
I also tried to install CCCP filters but nothing changed
Windows 10 Windows Media Player 12 AVI playback pixelated
Edit [May 18, 2016]: The default MPEG-4 H.263 codecs shipped with Windows 10(and possibly Windows 8) Windows Media Player 12 are faulty on NVIDIA cards and cause pixelation. Use the 32-bit version of
answers.microsoft.com
I also tried to install CCCP filters but nothing changed