I have read through the DTV recommended esata list. Here is what I have: a new HR 21-200 Thermaltake Max 5 Active Cooling Hard Drive Enclosure - http://www.amazon.com/gp/product/B004G8QETS/ref=oh_details_o00_s00_i00 Western Digital AV-GP 2 TB SATA II Intellipower 64 MB Cache Bulk/OEM Internal Hard Drive - WD20EURS - http://www.amazon.com/gp/product/B0042AG9V8/ref=oh_details_o02_s00_i00 This didn't work for me. After much trial and error, here is what is happening. 1. The ThermalTake Enclosure + the WD 2TB drive do NOT work with the HR 21-200. (This is the setup I was hoping for, since all that equipment is new) 2. The ThermalTake Enclosure + the WD 2 TB drive does work with the HR 20-700. ( an older DVR I have) 3. The ThermalTake Enclosure + an (older) WD 1 TB drive works with an the HR 20-700. 4. The WD 2TB drive + an (older) Antec XM enclosure I have work in the HR 21-200. So basically, the Thermaltake and the 2TB HDD does work in the old 20-700 but not the new 21-200. By working things around and switching things around, I know the TT enclosure is not defective, the 2TB HDD is not defective, the Esata port on the HR 21-200 is not defective. But there is something about the combination of the TT enclosure and the 2 TB drive should work but doesn't. I know you could say I should just use the Antec XM but it is older and makes alot of noise. Plus I really like the TT one, because of the way it cools. So does anyone have any idea about why this would be happening? Everything is in working order except when you combine the TT with the 2TB with the HR21-200. For some reason, it's like the HR 21-200 and the TT do not mix well but it is a setup many people have. The HR 21-200 is the new DVR I have so that is why I want to upgrade them HDD on it to 2 TB. The HR 20 is on it's way out.... Sorry if this is posted in wrong section.