To get it out of the way, I am paranoid and like to be sure without any doubt that my new drive is identical to the old. Acronis, which could be a faultless program, should never rely on the hardware writing correctly to the new disk or reading correctly from the old. "Crosstalk" and a number of other errors in transmission can occur. To start: I cloned my system disk using True Image 10's "Automatic" mode under "Clone Disk". Then I stepped away for the day and when I returned the clone was successful. Was the cloned disk compared to the original disk to verify the bits? If so, what technique was used: bit by bit or a CRC32 checksum/hash? My reason for suspicion: There was no option to verify the clone on "Clone Disk." According to the manual, this is only available in backup archive creation. Considering the manual says this preset is Disabled, I am led to believe Acronis does not verify the Clone automatically since verification doesn't seem to be standard. Also, "Operation 3 of 3" of the Clone Disk summary was "Copy MBR". There was no verification operation, so I know that the data was not verified AFTER everything was written. My theory: My theory, and please correct me, is that Acronis does not explicitly do any verification AFTER the cloning is complete. Instead, the inherit function of the hard disks confirms transmission WHILE everything is being written. According to http://www.dataclinic.co.uk/hard-disk-crc.htm: There are 156,296,385 sectors on my new 75GB disk. Sectors are split into 514 bytes. Sectors are the smallest area files are written to on the disk. 2 of the bytes are reserved for a CRC checksum that evaluates the sector, and if the remainder is 0 the data is correct but if not 0 there is an error. Because of this, Acronis may not explicitly verify the data, but the drives do automatically. When data from disk source is transferred to disk clone, since Acronis does the clone in sector-by-sector mode once the data is cloned the 2 sector's 2 byte checksums are compared and both must equal 0. While this sounds great, according to http://www.ciphersbyritter.com/ARTS/CRCMYST.HTM, CRC can only detect 99.998 of all possible errors. That means I have 156,296,385 sectors, 512 data bytes each, I am looking at a possible 3126 bytes that may be incorrect. So even if Acronis relies on the error correction functions of the disks alone, the clone can still be imperfect. In summary: Exactly how does Acronis or the disks verify the cloning operation?? Thanks.