gimme5 :
My external Seagate 3TB is not able to be seen under "My Computer". When checking the disk through disk management, the disk is shown as "unknown, not initialized, 3.9GB", where it supposed to be 3TB. The disk has divided into multiple partitions and drive letters not appearing for any of them in disk management. Also when I went to disk management, I was prompt with a message to ask me to initialize the disk, clicking yes for either "MBR" or "GPT" option will lead to error message "The request could not be performed because of an I/O device error." As I have very important data in the disk, I don't really want to initialize or format the disk...
Appreciate anyone with similar problem to share their experience and solution. Thank you.
Unfortunately, if you can't communicate with the drive, then you can't access any of the data. If the external hard drive is out of warranty, I'd try removing the drive and placing it in another hard drive enclosure to eliminate that as a potential of issues.
But if you can't access it, then you're looking at a data recovery service. Your chances of recovering the data varies widely -- there's no way to tell just what the source of damage is -- and be prepared to pay up to and into the four-figure territory.
Sadly, the only dependable way to save important data is to treat important data as if it's important and have it properly backed up. It's a basic part of PC upkeep, similar to changing the oil in your car or the air filter in your furnace. The 3-2-1 strategy is a good rule of thumb for protecting important data, meaning that you want three copies of all important data, two that are local and on different devices/storage mediums, and one copy that is off-site, such as cloud backup or even a flash drive in a security box.