http://www.bestbuy.com/site/Western...Id=9958432&st=western digital esata&cp=1&lp=1 Hello everyone, Just got a HR21 as a replacement. I figure I lost everything already so why not add on more space so we wouldn't have to worry about erasing shows. I just picked up the following HD from BB (Link Above). It states specifically on the box its a AV DVR expander and has DirecTV compatible on it. Reads on the back that HR21 is one of the compatible models. Went through the steps on how to hook it up on here and it doesn't go through the formatting steps. I decided to unplug the HD and record a quick minute of some thing so it's on the internal HD just to be sure. Went through the steps again and did the same thing. Checked the list and recording was still there so I know the external HD isn't recognized. What am I doing wrong? Any help would be greatly appreciated.