Why is the internal hard drive not available when attempting to install Ubuntu 18.04

[linuxguiri]

When I attempt to install either Ubuntu 18.04 or 19.10 from a USB flash drive to a Dell Latitude 5500 PC, only the USB drive appears on the "Allocate Drive Space" screen (as sda); the internal hard drive (SSD) is not visible. In other words, I can only install Ubuntu to the USB flash drive; the hard drive is not an option. How can I make the hard drive visible so that I can install to it?

[CelticWarrior]

You need to change the SATA mode from whether it is, usually RAID, to AHCI. But be aware that if you want to have a dual-boot with Windows you need to install AHCI support before making the change or Windows won't boot.

[oldfred]

Dell issues are often common across many models.

Some others in 5000 series but even others may be similar.
Dell Inspiron 5491
https://askubuntu.com/questions/1191...n-5491-freezes
Dell Precision 5530
https://ubuntuforums.org/showthread.php?t=2420905
Dell 5230 with 3 m2 drives.
https://ubuntuforums.org/showthread.php?t=2406057
Dell Latitude 5490 M.2 PCIe SSD
https://ubuntuforums.org/showthread.php?t=2405822

[Autodave]

Are you attempting to dual boot? Have you disabled fast start in the BIOS?

[CelticWarrior]

Are you attempting to dual boot? Have you disabled fast start in the BIOS?

Actually is Fast Boot and in UEFI
Fast Startup is another thing, a Windows 8+ feature (that should be disabled as well for a proper dual-boot).

But the thing is: Neither feature has anything to do with the internal drive not being detected.

[linuxguiri]

Thank you so much for your advice and suggestions, CelticWarrior, oldfred, and Autodave. In this particular case, CelticWarrior was right: The problem was that it was in SATA mode.

In case anyone stumbles onto this thread, for completeness, I'll write all of the steps I took to get Ubuntu 19.10 installed alongside Windows 10 on a DELL Latitude 5500 SSD using a USB drive:

Ubuntu 9.10 Dual Boot USB installation with Windows 10 on DELL Latitude 5500 SSD

1. Disable Windows Fast Startup (See https://www.windowscentral.com/how-d...0-fast-startup for more details.):
2. In Windows, open Power Options
3. Select “Choose what the power buttons do”
4. Select “Change settings that are currently unavailable”
5. Uncheck “Turn on fast startup”

Change from SATA to AHCI mode
(See https://www.tenforums.com/customizat...raid-ahci.html and https://support.thinkcritical.com/kb...id-ide-to-ahci for more details.):

1. In Windows, run MSCONFIG (as administrator)
2. Enable Safe Boot (minimal)
3. Restart
4. At DELL boot up screen, press F2 to enter UEFI/BIOS setup.
5. Select SATA Operation from System Confirmation and change to AHCI
6. “Are you sure you would like to continue?” Yes
7. Boot in safe mode (happens automatically)
8. Run MSCONFIG (as administrator) and disable Safe Boot.
9. Restart Windows

Resize Windows partition via Disk Management to allocate space for Ubuntu
(See https://mashtips.com/install-ubuntu-...oot-windows10/ and https://www.pcsuggest.com/dual-boot-...d-ubuntu-uefi/ for more details. Also helpful: https://partition.toolpie.com/)

Install Ubuntu (see https://mashtips.com/install-ubuntu-...oot-windows10/ and https://www.pcsuggest.com/dual-boot-...d-ubuntu-uefi/ for more details):

1. Insert bootable Ubuntu USB
2. Restart
3. Press F2 to enter UEFI/BIOS setup
4. Change Boot Sequence to boot from USB drive first (may need to add USB drive), apply and exit
5. Select Try Ubuntu and confirm Ubuntu works on system
6. Click install Ubuntu
7. At Installation type screen, select “Something else” or “Install Ubuntu alongside Windows 10” (See https://mashtips.com/install-ubuntu-...oot-windows10/ and https://www.techsupportpk.com/2019/1...dual-boot.html for more details. Also helpful: https://www.convertunits.com/from/GB/to/MB)