USB device not recognized

@supersnil wrote:
does the clip not work if there is realplayer instead of media player???

The point is that you either have to use your Clip in MSC mode (see above), or use it in MTP mode but then you need MTP drivers installed on your computer.  Installing RealPlayer doesn’t install MTP. 

What operating system are you using, and do you have Windows Media Player installed (if so, what version)?