Scott Mueller's Upgrading and Repairing PCs Forum

System:
MB = Gigabyte H310M S2H GSM
RAM = 32 GB
CPU = i7 8700-K
PS = Corsair RM750X
C drive = Samsung SSD 1 TB 970 EVO PCIe NVMe MZ-V7E1T0E M.2
Seagate 6TB ST6000NM0115
Seagate 4TB ST4000DM004
STA AC 35FCREADBU3 USB 3.0 Internal Multi Card Reader

I installed Win10 Pro 64 bit. The BIOS showed only the M.2 C drive but neither of the Seagate drives. Nothing in Windows showed any of the Seagate drives except when I was playing around with the "Create Storage" wizard. It sounded like a RAID creation operation and I didn't want to do that so I backed off.

I updated the BIOS and can now see all hard drives in BIOS. I can also see the Seagate drives in Device Manager and it shows that are all working properly and the drivers are up to date.
Device Manager and Disk Management also show 4 additional drives from the card reader.
I also downloaded a disk management app (similar to Acronis Disk Director) and it couldn't see the Seagate drives either.
How can I get Disk Management and ThisPC to see the two drives so I can start using them?
Thanks,

I cannot see the Seagate drives in Disk Management or in ThisPC (My Computer).

I would reinstall Windows from scratch after updating the BIOS. Let me know what you find. Scott.

I tried to reinstall but when I formatted my M.2 drive, Windows couldn't find any drives or partitions even though it was highlighted on the list. When I removed the M.2 drive from the MB Windows couldn't see the other two drives either and asked for storage drivers to be installed.
I'm going to try formatting and partitioning the M.2 on my other computer and see if the new computer can recognize it but I'm going to have to wait until just after Christmas for a M.2 to USB 3.0 adapter to arrive from Amazon.
I'm starting to suspect my problems are M.2 related. The MB is supposed to support two M.2 PCIe units but the connector only accepts one.

I got the M.2 to USB adapter and used it to plug the M.2 drive into my Windows 7 machine. I reformatted it and partitioned it to NTFS. I put the drive back into the Win10 machine and it was recognized by Windows installation and my Win10 installation is complete.
All drives were recognized by the BIOS before installation but the Win10 installation disk only recognized the 1 TB M.2 drive as an available drive to do the install on.
Once Win10 was installed, all drives appear in Device Manager under "Disk Drives" but only the M.2 "C" drive appears in ThisPC (My Computer) and in Disk Management.

I played around with "Manage Storage Spaces" and it does see my two additional drives and will format them and allow them to be seen in ThisPC. However, Win10 insists that I pool those two drives together into one drive. I don't want a single 10 TB storage space. I want a 4 TB space for my 4 TB drive and a 6 TB space for my 6 TB drive, each with their own drive letter.

I tried deleting the 10 TB storage, unplugging the SATA data cable from the 6 TB drive and rebooting. I created a storage area of 4 TB with my 4 TB drive. It appeared in ThisPC. Then I shut down, plugged in the 6 TB drive, rebooted and tried to make another storage area of 6 TB. No joy. Win10 insisted that I add the new drive to the 4 TB I already created.

I'm thinking that this "Manage Storage Spaces" is only for setting up simple RAID arrays and nothing else. I wouldn't waste my time with it but it is the only part of Win10 that seems to recognize my 2 additional disks besides Device Manager.
Surely Windows must have a way of adding a useable formatted and partitioned disk without making it into a RAID array.

Problem solved! While I was looking around in Windows 10, a contact box opened up with a chat option. I chatted with a Microsoft rep and he found a solution.
I opened a cmd prompt and entered:
diskpart>list disk>select disk 1>attributes disk clear readonly>online disk>convert mbr>exit

I rebooted and the two disks were seen by Disk Management - both of them even though I only selected disk 1 on the list in the cmd prompt. Disk 1 (the 4 TB disk) showed up as two 2 TB partitions of unallocated space but I converted to MBR and combined them. The 6 TB drive showed up as the full 6 TB the first time around.

Excellent, thanks for letting us know the solution. Scott.