Please check the below to the files are compatible with COWON C2.
* Video Format - AVI, WMV, ASF
* Video Codec - XviD SP/ASP, WMV 7/8/9
* Video resolution - 320x240, 30fps
* Audio Codec - MPEG1 Layer 1/2/3, WMA
* Subtitle - SMI
Please check the file information with COWON Media Center- JetAudio. If your file is not playing on COWON C2 even though your file is encoded with those specifications, your file might be damaged. Please convert the file again by using COWON Media Center, JetAudio for use in COWON C2.