Installation of Windows 10 on SSD while HDD is not removed

[Asad Sultam]

Hello Community!
I need a brief help.

I have Dell Inspiron 5570. It has an M.2 Nvme SSD slot. 
I bought a model of Samsung 970 evo. Now I have already 1TB HDD installed with files in it. I want a clean install on SSD. Now I have searched it many places. But there are some confusions still left out.
First of all, I saw one of the posts here, in steps, they said disconnect HDD and then set BIOS as:
1. Set SATA operation from Raid ON to AHCI.
It's okay to do this. They say after installation is complete, connect HDD again and it will appear in Computer as external disk (will it actually happen exactly as it?)
But isn't it possible to keep my HDD disconnected and install windows?
Help is needed at this particular points.
Secondly, on Dell website, they say:
Directly quoting:
"The current workaround is to disable all the SATA Storage device (HDD/SSD) controllers in the system Basic Input/Output System (BIOS) before performing the Windows 10 install to the NVMe SSD from Dell media.

After disabling the SATA Storage Device, you also have to make sure the BIOS is setup correctly by following these Steps:

Enter the BIOS by pressing F2 multiple timnes while the Dell Logo is shown.

Navigate to Boot Sequence and set Boot List Option to UEFI

Navigate to SATA Operation and choose AHCI

In Advanced Boot Option you click on Enable Legacy Option ROMs

Set Secure Boot to Disable

Once the Windows installation is completed, the SATA Storage Device controllers can be re-enabledwithout any issues and both the NVMe drive and the SATA drive(s) will function normally."
Detailed on this link: https://www.dell.com/support/article/us/en/19/sln301036/windows-10-install-with-nvme-ssd-and-sata-drives?lang=en

Now, this article does not clear (whether I disconnect HDD or  not) and also, if uefi option is enabled, all legacy options will disappear, which basically lists all boot options. So if HDD connected, and I install windows after uefi enabed, how it will install on M2 SSD?

Kindly help.
Thanks
Asad

[Electronics Wizardy]

Dont worry about unplugging the hdd, its mainly a precaution to prevent windows from installing on the wrong drive

 

   Just boot from the installer and select the ssd.

[KarathKasun]

12 minutes ago, Electronics Wizardy said:

Dont worry about unplugging the hdd, its mainly a precaution to prevent windows from installing on the wrong drive

 

   Just boot from the installer and select the ssd.

Its to keep Windows from being an idiot and installing the system on BOTH drives.  If the installer does this and you upgrade the storage drive, you will need to reinstall windows again.

[dfsdfgfkjsefoiqzemnd]

4 hours ago, Electronics Wizardy said:

its mainly a precaution to prevent windows from installing on the wrong drive

Actually no, it's because Windows has this nasty habit of putting the bootloader on a different drive than the OS itself. 

[LogicalDrm]

14 hours ago, KarathKasun said:

Its to keep Windows from being an idiot and installing the system on BOTH drives.  If the installer does this and you upgrade the storage drive, you will need to reinstall windows again.

Windows doesn't install on multiple drives. Bootloader is different, and that can be super-problemnatic. But OS itself doesn't install over multiple drives.

[KarathKasun]

5 hours ago, LoGiCalDrm said:

Windows doesn't install on multiple drives. Bootloader is different, and that can be super-problemnatic. But OS itself doesn't install over multiple drives.

The bootloader is part of the OS, so it actually is installing itself on multiple drives.

 

OS without a bootloader is useless.  Bootloader without an OS is useless.