I looked through the eSata threads, and could not find this specific issue. Please forgive my noob question. I have the HR21 DVR. My one mistake was purchasing hardware before reading the recommendations, however, if I am reading things right this is one of the configurations that works. Vantec Nexstar 3 eSata enclosure with WD GREEN 1TB HDD. When I do the sequence of power down the DVR, unplug it, wait for awhile, plug in the HDD via eSata cable in the SATA port on the back of the DVR, power up the HDD and let it spin up, then plug in the DVR and turn it on.... What I get is a repeating loop of restarting after "Running receiver self-check". It goes black, then back to "Almost done... a few seconds more" and then back to "Running receiver self-check". I does this over and over. Is this simply that it does not see the HDD? I did not do anything special with the HDD, just unpacked it, put it into the enclosure per the instructions, and plugged it in.