iPod classic 120 GB malfunction

My ipod is the Ipod classic 120GB recently when connect to the computer, it appears on the computer screen as :

USB device not recognized.

One of the USB devices attached to this computer has malfunctioned, and Window does not recognized it.

And it appear in bold type in the diagram of USB Root Hub that the Ipod device was Unknown Device

How could I correct this problem or what could I do to make my ipod function normally ? Because without the recognition of my Ipod of my computer, I cannot do any new sync or change to the media already stored inside recently.

Beside, I don't remember if the Ipod classic 120 GB device had come with the CD program to install the device program with the computer or not ? If it wasn't necessary than what I need to do ?

Thanks in advance.