Can't install manjaro with 2 primary partitions available!

I have windows 10 installed and I want to dual boot manjaro alongside windows 10. but the problem is manjaro detects my Bootable USB as primary drive. and with adding up 2 primary partitions for windows 10 and one USB we have 3 primary partitions. when I want to install manjaro it will create swap partition and when it wants to create root partition it shows a fail error. i’m completely sure the problem is with primary partitions. why is my USB a primary partition. I recently had ubuntu installed and it doesn’t have this kind of problems.

Welcome here, @Graham1384

Switch off secure boot in your firmware (in case it’s activated), run a Manjaro live ISO and open a terminal window to provide output of

inxi -Fazy
sudo parted -l

to share the minimum system information required to help you.

Do you know if you are booting in UEFI or in BIOS (legacy) mode?

Manjaro is not Ubuntu - and there is a huge difference.

One of the differences is that Ubuntu along with a few other major distributions has bought into the Microsoft certificate supply chain for secure boot - which in turn enables Ubuntu ISO to be allowed to boot on Windows systems.

@Wollie already mentioned this - but I suspect the problem to go deeper than that.

Please verify if Legacy boot or Compatibility mode is enabled in your systems firmware. If it is then disable it and restart your system.

What probably happens is - because Manjaro ISO is a hybrid ISO - can boot both Legacy (MBR style) and EFI - a system with Legacy boot enabled tries Legacy first - then EFI - then you find yourself a situation where the system is EFI booted as MBR - which severely limits the number of supported partitions to four (4) and an almost impossible situation where you need to know exactly what you are doing.