Help in finding free MPEG-2 codec for WMP ?

    Iam having a hard time finding a codec for WMP ver10 ,a MPEG-2 codec compatable with WMP ? I have two MPEG-2 codes listed that are from my Sonic app by Roxio one is cinemaster video decoder ver 4.0.0.46 the other is also supplied by Sonic MPEG listed as Sonic MPEG Video ver5.0.0.1 ?  One of the the cionemster version is compatable with my MCE and that was the codec that allowed my ATI TV Wonder to work properly allowing me to access live TV on my desktop ! However both codecs are maked wiith a red X as not being compatable with Widows Media Player ? Any help greatly appreciated !

                                                                                               Thank You ,Nick 

XPS400 2.8Gig 820 D Dual Core -VIIV
O/S WinXP Media Center Edition 2005
3 G.B. DDR2 RAM PC5300 - 2-1G.B. 2-512M.B.
Samsung Hard Drive 250G.B. 7200RPM
Seagate externial 320G.B. H.D.7200RPM USB
ATI 128M.B.HYPER Mem PCI-E X16 X300SE.DIM
ATI TV Wonder Elite PCI
19" FP
Sigma-Tel Intergrated Audio 7.1 channel
Logitech G15 Keyboard
DVD-/+RW & DVD-ROM
Pertelian X2040 ForeSight Systems LCD information Display
Dell 944 AIO Printer
EASYWATCH LCD System Monitor /Fan Controller

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