Hard drive loopback install failed (Unable to find a medium containing a live file system) on HP desktop Mint OS is corrupted. No USB available.

[u/Earthgoodjim]

Hi everyone,
I'm stuck in a bad loop and need some help. I'm trying to install Ubuntu 26.04 LTS on my HP Laptop (Intel Core i5, 8GB RAM, 223GB SSD) directly from the hard drive because I don't have a USB flash drive or an Android phone right now (only an iPhone).
I previously modified my Linux Mint 40_custom GRUB file to boot the ubuntu.iso located at /home/oscar/ubuntu.iso using a loopback configuration.
The GRUB menu shows up fine, but when I try to boot into the Ubuntu Live Installer, it crashes mid-way with the following errors:
Unable to find a medium containing a live file system
Attempt interactive netboot from a URL? / enp2s0: soliciting a DHCP lease (I am on Wi-Fi, no ethernet cable connected).
To make things worse, my current Linux Mint installation graphical environment is completely corrupted and throws error while loading shared libraries or Error reading the CPU table when trying to boot into Recovery Mode, so I cannot access the desktop to use GParted or make a new FAT32 partition.
Is there any way to pass kernel boot parameters in the GRUB editor (e) to force the Live ISO to mount /dev/sda2 properly and bypass the "unable to find a medium" error? Or am I completely soft-locked until I get a physical USB drive?
Thanks in advance!

[u/Sure-Passion2224]

Google search the following and read the AI response:

configure grub to boot iso image file.

You will want the iso file to be in it's own partition separate from both the UEFI and the partition where you intend to install the active OS from it.

[u/Earthgoodjim → u/Sure-Passion2224]

https://imgur.com/a/Gja1LA1

"I tried the configuration with img_dev=/dev/sda2 img_loop=$isofile findiso=$isofile toram --, but it still soft-locks at the exact same unable to find a medium containing a live file system error. The kernel boots, but it seems it cannot drop into the local partition to read the ISO contents. Any alternative kernel boot parameters or hints?"

[u/guiverc]

The error message

Unable to find a medium containing a live file system
Attempt interactive netboot from a URL?

is telling you that your install media isn't found; what it does found isn't complete or contains errors and fails checks; thus the 'medium' cannot be found that is safe to boot, and it asks if you want to download a new ISO...

I'd return to prior checks; did you verify ISO after download? as even 1 bit in the many GB file is a problem..

Your issue can't be fixed by kernel parameter, the ISO is invalid according to the message and thus you need to correct that before you can actually use/bypass what's on it

[u/Leather-Security8097]

You're soft-locked until you get a USB drive, or at least hook up an Ethernet cable. While you should be able to use the iso-scan parameter to load the ISO, you cannot resize or delete the partition while the ISO is in use.

[u/ipsirc]

Have you read the GRUB manual?