How do I set the BIOS for GPT

[drmeyers381]

Do I need to set anything in the BIOS my computer to boot so I can Install Windows 10 Pro to a 4TB HDD. I have a CM6870/DP MB.

 

[R4lNM4N]

I would only worry about this if your MB was circa 2005 which it is not. It should be set already but look for a setting saying either "UEFI" or "UEFI and Legacy" boot. Unless you went into your BIOS/UEFI and intentionally turned off a UEFI feature, the Windows install should be able to partition it as GPT. Regardless, the system will install.

The issue is that old BIOS' cannot boot to a partition larger than 2.2TB. If your system is somehow not compatible, it will still install. It will create a 2.2TB MBR partition for the windows install and leave the rest as unallocated.
The remaining (unallocated) space will still be usable - just another partition.

Install Windows and then go straight to the computer management console. Under disk management, you should see one large partition and a number of smaller "system" partitions that Windows will create. These are for system recovery/restore/etc. I digress...

If you see your main partition is only 2.2TB and you have a separate, large, unallocated partition, then you'll know it didn't install as GPT. Alternatively you can:

Go to Control Panel > Administrative Tools > Computer Management, and select Disk Management
On the left of the right lower pane, right-click on Disk 0 and select Properties.
Select the Volumes tab.
The Partition style: entry will show as either Master Boot Record (MBR) or GUID Partition Table (GPT).

 

[Calvin7]

The motherboard is listed as having a 64 Mb Flash ROM, UEFI BIOS. You need to do a UEFI install of Windows 10.

How to create a bootable UEFI USB drive with Windows 10 Setup
https://winaero.com/blog/how-to-create-a-bootable-uefi-usb-drive-with-windows-10-setup/

SATA configuration in BIOS is by default set to [IDE]. You need to change that to [AHCI].