How to mount 3TB HDD to non-UEFI Windows instalation

[shh_a]

I have to move large amount of data from and to an external HDD, so decided that it will be way quicker and troublefree if I attach the HDD to SATA port instead of using the USB 3.0 interface.

OS is Windows 7 64bit legacy instalation on some SSD;
SATA controller in on AHCI mode;
The motherboard is ASUS Z87 Deluxe;
The HDD is some 3TB WD Green from WD My Book

When I attach it, the system either does not want to POST or it's giving me blue screen. Usually it takes one unsuccessfull atempt to POST and next time it starts loading OS without any luck. But recently the system even does not want to POST with the HDD attached. If POST is succesful, the drive is shown corecctly in BIOS.

Also I tried to mount the HDD after loading OS thru eSATA port, but then OS says that I have to format the volumes. The first time when I did it, Disk Managemen showed that the HDD has two NTFS partitions and one 300MB "GPT Protective Partition" - as it's shown if I connect it to the USB 3.0 port. After restart showed 38MB "GPT Protective Partition", two RAW partitions and two unallocated volumes!!!

Am I missing something and is there any way to use the HDD on SATA port without removing my data and formating it in some way.

P.S. And even if I format it to be able to use it on non-UEFI instalation, then will I be able to use it on my external HDD box? Thanks in advance for your help!

 

[ArtPog]

It appears that you're basically dealing with a 3 TB HDD that for all practical purposes is devoid of data. It's highly doubtful that you can restore whatever data was contained on that drive. You can try various "recovery" type programs available on the net. If the data if particularly important/crucial to you then you might consider a commercial data recovery company.

In any event first do a Google search on "recovering data from a drive with a GPT Protective Partition"

Otherwise, use Diskpart to "clean" the drive; initialize it with the GPT-partitioning scheme and then format/partition the disk and use it as your secondary drive.

 

[shh_a]

I was able to see my data when the HDD is in it's enclosure. Turns out the problem is in the way the HDD was formatted. WD states that their drives are Windows XP compatible. Only 32bit Windows XP can't read/write to GPT disks, 64bit Windows XP Pro, all Vista, 7, etc. can read/write to GPT disks no matter if it's UEFI or legacy boot. Didn't know that but wikipedia was usefull - https://en.wikipedia.org/wiki/GUID_Partition_Table#Protective_MBR_.28LBA_0.29

So, what I did:
First downloaded all needed data thru the USB port. Instead of copying everything in one go, I did it using 20-30GB chunks wich is good not only because of the the inreface/OS, but also good for both drives - I read somewere that there is significant risk of drive failure after a user has done a very large transfer of files/disk activity is high in a short amount of time.

Then I tried some freeware programs to rebiuld/convert to GPT or MBR without data loss. No succes when the HDD was in it's enclosure which is logical because of the firmware of the enclosure. Then I attached it thru the esata port of my case after OS was loaded. Since I didn't have important data, didn't bother much with these programs and deleted the volumes using Disk Managemet, converted to GPT disk and created one NTFS volume. I didn't use DISKPART/clean and guess what happened when I put the drive back in it's enclosure to make sure if it's save to write data - the firmware rebuilded the the previous format with two NTFS volumes and all the data. So I realised that if I want to use the drive properly in it's enclosure, I have to format it using some WD tool.

The strange thing is that when I attached again the HDD to motherboard's SATA port, the PC booted fine and the OS was showing that the HDD is GPT with only one volume!!!

Downloaded WD Quick formatter and while the HDD was in it's enclosure choosed "Factoty defaul" instead of "XP compatible" and copied some "test" file for safe purpouse. I guess that this tool also determines the way that the firmware in the encosure comunicates with the HDD and prevented the restoring of the previous format.

Now the drive can be used either in it's enclosure or thru SATA port without data loss or POST/boot issues. Which I think it's safer in case that you damage somehow the enclosure. The bad thing is that WD did't add the opition to convert without data loss their HDDs form GPT to "XP compatible" and backward, which I'm sure it's possible since they can rebiuld "XP compatible" format without data loss.