This is the part that "sounds" very different from previous experience. At first sight, it seems like *something* *somehow* changed the drive map, putting a "Cap" on it. You can *try* (of course with NO guarantees whatsoever) to reset the drive to deafult values with a F,,22 , but really cannot say if it can be of any use. Read around here: http://www.msfn.org/board/topic/128807-the-solution-for-seagate-720011-hdds/?p=985252 AND given link: http://www.msfn.org/board/topic/128807-the-solution-for-seagate-720011-hdds/page-19#entry832570 @Mrich0908 Nice to know , but of course *anything* that can send/receive TTL (at the right "low" TLL level) would do, usually people "playing" with Arduino's also have one or more suitable USB to TTL or Serial to TTL converters, and - more than that - they usually know how to interface things successfully, so I am not surprised that it wasn't mentioned before as posters on this thread - usually - post here looking for help/support as they are not familiar with the matter, while most people knowing where their towel is will simply run the commands an unbrick the drive, without ever posting about their experience. Thanks for sharing it . jaclaz Thank you for help! I tried command, according to description. I received the following response from the Hyperterminal: Rst 0x20M ASCII Diag mode F3 T>/2 F3 2>Z LED:000000CE FAddr:0025DF1F Rst 0x20M ASCII Diag mode F3 T>/2 F3 2>Z Spin Down Complete Elapsed Time 0.131 msecs F3 2>U Spin Up Complete Elapsed Time 8.900 secs F3 2>/ F3 T>F,,22 Drive Configuration restored to defaults. RAW OFF RWSWD-OptChange: Ctrl 0001 Dvgas 0008 Rvgas 0008 Fvgas 0008 SumOf 0008 WriteCapInfo Selection = 0000 CurrentCap 00000000 HDACap 74706DB0 Update Cap and Save CurrentHDA 74706DB0 HDACap 74706DB0 NativeCap 74706DB0 48BitCap 74706DB0 28BitCap 0FFFFFFF SaveCapInfo (P) SATA Reset PASSPackage Verified F3 T>m0,2,2,0,0,0,0,22 ţ Rst 0x20M (P) SATA Reset PASSPackage Verified ReadCap successful - set 48Bit <- Current = 74706DB0 RWSWD-OptChange: Ctrl 0001 D vgas 0008 Rvgas 0008 Fvgas 0008 SumOf 0008 (P) SATA Reset Package Verified No Phy: Staggered spin bypass ASCII Diag mode F3 T> After that, the real size was visual n the BIOS. However in the windows it was still in "not initialized" state, the contents (data) are not visual. Than I connected the HDD to the adapter again, than when I opened the hyperterminal I got the following message: Rst 0x20M (P) SATA Reset PASSPackage Verified ReadCap successful - set 48Bit <- Current = 74706DB0 RWSWD-OptChange: Ctrl 0001 Dvgas 0008 Rvgas 0008 Fvgas 0008 SumOf 0008 (P) SATA Reset Package Verified No Phy: Staggered spin bypass ASCII Diag mode F3 T> Earlier I have not seen this message: "No Phy: Staggered Spin bypass" How can I save the datas?