©ASUSTEK COMPUTER INC. ALL RIGHTS RESERVED.

SumTingWong · ‎04-29-2018

ASUS Maximus VII Hero Z97
i7 4790k @ 4.5GHz
32GB Corsair RAM
1TB HDD
256GB SSD
3TB HDD
CD/DVD optical drive

I have 4 drives that are connected to the motherboard top 4 SATA ports. Out of the 4 drives, only 2 showed in Boot Priority which are my OS SSD and my optical drive. My 2 other hard disk drives were not showed up in the boot priority, but it does showed up in boot menu, SATA Information on the EZ Mode tab, Boot Override tab in the Advanced Mode, and Hard Drive BBS Priorities. Boot Device Control was set to UEFI and Legacy OPROM. Lauch CSM was enabled as well. My two hard disk drives have drive letter. Please help me out fam. I don't know what's going on and how to fix it. If I try to power on individual drive, the motherboard will display it in the Boot Priority, but if I try to power on all my 4 drives, only 2 drives will display in Boot Priority. I don't think my HDD is dead because Windows are able to detect my two hard disk drives.

I have Fast Boot > Enabled
SATA Support > All Devices

USB Support > Partial Initiation

PS/2 Keyboard and Mouse support > Auto

Network Stack Driver Support > Disable

Next Boot after AC Power Loss > Fast Boot

The thing is if I try one drive at a time, it will displays it in the Boot Priority. But if I try all my 4 drives at the same time, only 2 will display which are my OS SSD and my optical DVD/CD drive. I did tried my laptop hard drive to see if my 2 hard disk drives are dead, and the result is the same as before. Only my OS SSD and my optical drive display in the Boot Priority.

pndiode · ‎04-29-2018

Boot\CSM (Compatibility Support Module)\Launch CSM - Disabled

Boot\CSM (Compatibility Support Module)\Launch CSM - Enabled

I had a problem with two Hard Drives not showing that were made in 2010, but they worked fine. I replaced them when they started disappearing and appearing in windows.

R5Eandme · ‎04-29-2018

Hello,

I think the behavior you are seeing might be perfectly normal. When I was learning about UEFI booting (CSM disabled) vs. legacy booting (CSM enabled) I was at first confused why some devices didn't show in the boot list with CSM disabled. Only devices with the UEFI boot manager will show, and will be labeled Windows Boot Manager or UEFI: device name, etc. These devices contain the EFI directory with the UEFI boot manager as EFI/BOOT/bootx64.efi or EFI/BOOT/bootmgfw.efi
But with CSM enabled, any boot-capable device will show in the list, even those not set up for UEFI boot with the EFI/BOOT directories. You might be interested in this post:

https://rog.asus.com/forum/showthread.php?96196-I-need-advice-on-CSM-and-Secure-Boot-settings

SumTingWong · ‎04-30-2018

R5Eandme wrote:
Hello,

I think the behavior you are seeing might be perfectly normal. When I was learning about UEFI booting (CSM disabled) vs. legacy booting (CSM enabled) I was at first confused why some devices didn't show in the boot list with CSM disabled. Only devices with the UEFI boot manager will show, and will be labeled Windows Boot Manager or UEFI: device name, etc. These devices contain the EFI directory with the UEFI boot manager as EFI/BOOT/bootx64.efi or EFI/BOOT/bootmgfw.efi
But with CSM enabled, any boot-capable device will show in the list, even those not set up for UEFI boot with the EFI/BOOT directories. You might be interested in this post:

https://rog.asus.com/forum/showthread.php?96196-I-need-advice-on-CSM-and-Secure-Boot-settings

None of my drives labeled Windows Boot Manager or UEFI device name. My OS is installed on my Samsung SSD. In the BIOS, it displays Samsung SSD not Windows Boot Manager: Samsung SSD.

R5Eandme · ‎04-30-2018

SumTingWong wrote:
None of my drives labeled Windows Boot Manager or UEFI device name. My OS is installed on my Samsung SSD. In the BIOS, it displays Samsung SSD not Windows Boot Manager: Samsung SSD.

Well, if boot priority list does not show Windows Boot Manager or UEFI: then maybe you don't have a UEFI boot but a legacy boot instead? Your Samsung partition for legacy boot could show as few as two partitions, a "system" partition and a "boot" partition. The boot partition is actually the C:/ drive with the OS installed on it. If you can verify that you have legacy booting and not UEFI booting then it may be that the Seagate and WD HD don't show in the boot priority list because they were not designated as bootable when they were partitioned. That is they don't have the "boot flag" set.

So, regardless of whether you have a UEFI boot or a Legacy boot, there are valid reasons why the Seagate and WD HD would not show up in the boot priorities list. Still, you can use them for data storage?

SumTingWong · ‎04-30-2018

pndiode wrote:
Boot\CSM (Compatibility Support Module)\Launch CSM - Disabled

Boot\CSM (Compatibility Support Module)\Launch CSM - Enabled

I had a problem with two Hard Drives not showing that were made in 2010, but they worked fine. I replaced them when they started disappearing and appearing in windows.

I can't boot with CSM disabled. My motherboard will tell me to go back to the BIOS to enabled CSM. All my 4 drives don't show UEFI name or Boot Manager. I Have my OS installed on Samsung SSD. In the BIOS, it will displays Samsung SSD, and not UEFI: Samsung SSD or Windows Boot Manager: Samsung SSD.

SumTingWong · ‎04-30-2018

The pictures of my BIOS are here https://imgur.com/a/JzAtayM

R5Eandme · ‎04-30-2018

SumTingWong wrote:
The pictures of my BIOS are here https://imgur.com/a/JzAtayM

Hi SumTing Wong,

I see that you have an older motherboard with Z97 chipset, and you said "Boot Device Control was set to UEFI and Legacy OPROM. Launch CSM was enabled as well." Enabling Legacy OPROM means that older devices can be used for booting, and this requires CSM enabled: "Compatibility Support Module" allows for older boot devices. It appears that the BIOS considers only your Samsung SSD and optical disc drive to be bootable devices. The Seagate and WD HD and not considered to be boot devices. It could be that your boot type is UEFI, and therefore only devices that have the UEFI Windows Boot manager (i.e. Samsung SSD containing the partition EFI/BOOT/bootfwmg.efi) or can have the boot manager (e.g. Windows DVD install disk) will show up in the Boot Priority List. If you have UEFI booting, the Seagate and WD HD would not show up in the Boot Priority list because there isn't a Windows Boot Manager installed on them. I don't think this is a problem for you, and you should still be able to use the Seagate and WD HD for data storage.

You can detect if you are using UEFI boot type by running the Windows disk management console and look at the partition scheme for your Samsung SSD. It should be similar to the following, with an EFI partition present:

SumTingWong · ‎05-01-2018

R5Eandme wrote:
Hi SumTing Wong,

I see that you have an older motherboard with Z97 chipset, and you said "Boot Device Control was set to UEFI and Legacy OPROM. Launch CSM was enabled as well." Enabling Legacy OPROM means that older devices can be used for booting, and this requires CSM enabled: "Compatibility Support Module" allows for older boot devices. It appears that the BIOS considers only your Samsung SSD and optical disc drive to be bootable devices. The Seagate and WD HD and not considered to be boot devices. It could be that your boot type is UEFI, and therefore only devices that have the UEFI Windows Boot manager (i.e. Samsung SSD containing the partition EFI/BOOT/bootfwmg.efi) or can have the boot manager (e.g. Windows DVD install disk) will show up in the Boot Priority List. If you have UEFI booting, the Seagate and WD HD would not show up in the Boot Priority list because there isn't a Windows Boot Manager installed on them. I don't think this is a problem for you, and you should still be able to use the Seagate and WD HD for data storage.

You can detect if you are using UEFI boot type by running the Windows disk management console and look at the partition scheme for your Samsung SSD. It should be similar to the following, with an EFI partition present:

I figure out that my BIOS Mode was set to Legacy instead of UEFI, so I converted my OS Samsung drive to GPT without data loss. Now, I can boot into the OS with CSM disabled no problem. Also, in the BIOS it shows Windows Boot Manager: Samsung SSD and Samsung SSD in the boot priority as well as my optical drive. Unfortunately, my WD and Seagate HDD are not show up in the Boot Priority EZ Mode and Boot Option in Advanced Mode > Boot. Now, my BIOS Mode is UEFI instead Legacy.

I did created a UEFI bootable Windows 10 USB. If I want to do a clean install of Windows 10, do I have to disable CSM?

R5Eandme · ‎05-01-2018

SumTingWong wrote:
I figure out that my BIOS Mode was set to Legacy instead of UEFI, so I converted my OS Samsung drive to GPT without data loss. Now, I can boot into the OS with CSM disabled no problem. Also, in the BIOS it shows Windows Boot Manager: Samsung SSD and Samsung SSD in the boot priority as well as my optical drive. Unfortunately, my WD and Seagate HDD are not show up in the Boot Priority EZ Mode and Boot Option in Advanced Mode > Boot. Now, my BIOS Mode is UEFI instead Legacy.

I did created a UEFI bootable Windows 10 USB. If I want to do a clean install of Windows 10, do I have to disable CSM?

OK good! You were able to re-partition your Samsung boot SSD from MBR to GPT, and convert from legacy to UEFI boot. I had thought that you were stuck with legacy boot if you installed Windows with CSM enabled, but you have proven that you can convert the boot to UEFI and not lose any data. I learned something new. What steps did take to get to GPT and UEFI boot?

Unless the Seagate and WD were designated as bootable when they were being partitioned, they should not show in the boot priority list.

Good that you made a UEFI bootable Windows install USB drive. It is good also to make a Windows RECOVERY USB drive, it has lots of tools. I don't think that you need to re-enable CSM in order to use these Install or Recovery USB drives because they are UEFI-bootable. They should contain the following directory and file EFI/BOOT/bootx64.efi From what you were saying, you may only need CSM enabled if you are trying to do a legacy boot from a drive that is partitioned as MBR instead of GPT.

I am impressed how really complex the boot process is, and it gets more complex when they add security features like Secure Boot with digital signatures. So it isn't surprising when disk cloning sometimes goes wrong.

I am glad you got it figured out

My hard disk drives not showing up in boot priority