18.04 Install | disks not recognized for install

[utnubu3]

Problem: When doing a clean install of 18.04 via a Live USB on a Dell Latitude (which previously had Win7), no disk (volume) is recognized other than the USB itself. During Ubuntu install the error message displayed is: "You need at least 8,6 GB disk space to install Ubuntu. This computer only has 7.8 GB." (the latter refers to the 8 GB volume of the USB).
Which steps have been taken thusfar:
#1 Using Grub, running <grub>ls results in the following disks detected: (memdisk) (hd0) (hd1) (hd1, apple2), (hd1, apple 1), (hd1, msdos2). Running <grub> ls (hd0) indicates " no known file system is detected for" hd0. Running <grub>ls (hd1) indicates "filesystem type iso 9660 - label ubuntu 18.04.3 LTS amd64". In other words, the second hard drive hd1 already contains the ISO image of 18.04 but is not recognized.
#2. Using Gparted does not result in any other detectable drive other than the USB containing Gparted.
Question: how to ensure both drives of the laptop are recognized for Ubuntu 18.04 install ? The aim is a clean install of Ubuntu. No dual boot alongside Win 7, which has already been removed.

Any feed back and help is much appreciated, best Alex

[GhX6GZMB]

Sounds a bit like you're still on the live image.
When the live image completes, you'll have a graphics desktop with the icon "Install Ubuntu". You need to execute this, then your disk will be formatted to ext4.

[utnubu3]

Thanks. I can run Ubuntu via the USB, but install is not possible as the 125 GB hard drive is simply not recognized. The solution is possibly in (a) tweaking BIOS and/or repartitioning or (b) re-formatting the drive. Any suggestions are much appreciated.

[TheFu]

BIOS settings should be checked. ACPI, SATA, etc. What disk models and motherboard are involved?

[utnubu3]

Thank you. Laptop is a Dell Latitude E 6420 (built 2012). Memory: 4MB, DDR3 SRAM. BIOS is A16 revision. BIOS indicates the following:
(x denotes 'box ticked / on' / 0 denotes 'box unticked / off')
> Boot Sequence:
x Disk
x Internal HDD (IRRT)
x USB
x CD
x Onboard NIC
> Boot List Options
x Legacy
0 Uefi
> Sata Operation
0 Disabled
0 ATA
0 AHCI
x RAID on
> Drives
x SATA-0
x SATA-1
x SATA-4
x SATA-5

Any suggestions tweaking BIOS / drives to ensure Ubuntu recognizes the 125 GB hard disk for install would be much appreciated.

[oldfred]

I would check if you have updates to UEFI.
Windows started requiring UEFI in 2012, and early UEFI implementations often needed updates.

Newer Dell need drives changed from Intel RST/RAID to AHCI, not sure about older Dells. Is little x mean you have RAID.
If true RAID with two identical drives, do not change settings without major full backups. Best to have backups anyway.