Mint Cinnamon 64bit wont install

[k_zeon]

Hi. I have created a Ventoy USB and  have formatted the ISO partion as NTFS
I have put Mint 20 Cinamon on it. 64bit.
I have an old PC that has Legacy & UEFI.
I can boot to Mint in Legacy and it runs but not in UEFI
I have tried the normal install and screen freezes.
I have tried comatibility but it gets so far then stops at
ACPI: Video Device [VGA] (multi head:yes Rom:no Post:no)

Also just wiped a 16gb usb and installed Ventoy 21 and did nothing else.
copied linuxmint-20-cinnamon-64bit.iso to partition.
Set as UEFI boot mode and still refuses to load either normal or compatability
any help?

Further investigation and I have had Bios set as CSM = Disabled and Boot UEFI only
This does not work

Set CSM=Enabled and Boot UEFI and it works.

I thought UEFI booting did not require CSM to be enabled??
Pls advise why.

tks

[longpanda]

You can create a bootable USB with other tools (e.g. Rufus) and make a comparison test.
Then we can confirm that whether it's something about the BIOS or something about Ventoy.

[k_zeon]

You can create a bootable USB with other tools (e.g. Rufus) and make a comparison test.
Then we can confirm that whether it's something about the BIOS or something about Ventoy.

Hi Longpanda
I did a few edits and not sure you saw all text.
if you did then i can do the test you advised.
tks

[k_zeon]

so after hours of testing.
I have an old PC 2012 Lenovo that does have CSM & UEFI settings in bios
i have tried using Rufus to make a few different types of install usb sticks using
linuxmint-20-cinnamon-64bit.iso ( MBR , GPT , NTFS, 32Bit etc)

I have the PC set to boot Non CSM & Set as UEFI , and have Rufus make a stick as GPT - UEFI
I can boot USB and go through the install.
I set the correct partitions as GPT and then set UEFI partition and swap file and main partition
Every thing goes fine and seems to install
I then take out USB stick and it does not boot. error in the sqash file cannot be decoded.
I set the Bios to CSM - Legacy and says there is no OS installed.

Is it because i have an Old PC and can only install under Bios CSM & Legacy or am i missing something

I can install Linux Mint 20 under CSM + Legacy and it works fine, but wanted to try and see if i can do it under UEFI only

[k_zeon]

so ok, dont think its a Ventoy issue as every combination i created a usb stick with Rufus to get installed as UEFI only
did not work. It must be something to do with the pc and being old.!
I set the boot as Non CSM & UEFI only. created a usb with rufus and set as GPT - UEFI only
It boots and goes through the install and finishes.
I take USB out and it will not boot.

Can any else advise if they have installed Mint 20 64bit in UEFI mode only with not bios support.?
if yes then advise what you did and settings etc.