My Book Essential 2.0

Hi,
I got WDTV Live and its connected by USB to an external HD.
until now everything is gona be OK, but from the last week when I play every file, start finethe playing, but in 5 or 10 mins the fille is going to stop and in a few seconds continuos

Test:

  • I’ve copied some files from the external HD to my PC and  play them fine

  • I ran chkdsk utility but windows no found errors

  • I’ve plugged the external HD into my PC, and I’ve tried play the files but the problem continuos

  • I’ve try plug and unplug the device (this suggested me from this forum) 

Data:

My book size: 1 TB

WD TV Live firmware version: 1.02.21

My book age: 1 year

How can I fix My book?

thanks