My computer will not reconize my yp-t9j even after I down load the CD that came with it. can you please help me.

Try going into the settings and changing the USB mode or look for a setting called MSC mode it will work out of the box with just about any MP3 player and any OS (W*ndows, Linux). MTP mode will work as long as you have WMP 10 or 11 installed. Firstly, I will try to explain MSC mode and MTP mode and what they mean. MSC stands for Mass Storage Class. When your player is in this mode, the computer will see it the same way it would see a Thumb drive or flash drive, as a removable disk. It will assign the first available drive letter to your device, as well as one for the memory card (if it uses one and it is installed). This is probably the more popular of the 2 modes, and is a more "open source" type of standard. Most computers detect the player in this mode without a problem very well and right away.
MTP stands for Media Transfer Protocol. It is a Microsoft standard and is Microsoft's solution to connecting MP3 players and cameras to a w*ndow based Computer. MTP mode must be used in order to transfer ANY Digital Rights Management (DRM) protected content. MP3's downloaded form services like Rhapsody and Napster will only function in this MTP mode.
Most good MP3 players will have both of these modes at the users options.