Can USB v2.0 ports boot all bootable USB flash drives? Diff to USB v3?

I have a problem with two bootable USB flash drives with some Tools on it.

When I plug them into an USB v3.0 port then they boot successful.
When I plug them into an USB v2.0 port on the same computer then they are NOT booting.

Yes, in the latter case they appear in BootMenu as option to be booted.
However after selection and boot start they suddenly abort booting and the booting switches silently to the hard disk based WindowsOs.

The USB v2.0 ports seem to be ok. When I boot WinOS from hard disk and plug in USB flash drives I can read and write files from/to it.
The Bootcode of the USB flash drive is a Legacy BIOS and the computer runs with Legacy BIOS.

So what could be the reason for non-booting?

Is there a booting capability difference to USB v3.0 ports?

Peter

Are all of these ports part of the PC itself, and connected directly to the motherboard?

Attempting to boot off a USB add-in card, or external hub, can sometimes fail.

USB3 flash drives should be backward compatible.
When plugged into USB2 ports they should function at USB2 speeds.

A possible problem could be the driver.
A problematic driver may or may not be displayed in device manager.

As you're booting from the USB drive, Win 10 is off the problem.
What OS is on the USB drive?
Did you checked BIOS settings to see if the USB 2.0 ports are allowed to boot from?

If youre running UEFI with the CSM disabled, then the chances of any older Legacy style formatted USB drives from Windows 7 and before probably wont boot. Only an age factor thing.
For me with the CSM disabled, anything that hasnt been created on a UEFI system, shouldnt be able to boot.
Version 2.0 or 3.0 would make no difference. Only factor being what system it was created on

Pluginz said:

For me with the CSM disabled, anything that hasnt been created on a UEFI system, shouldnt be able to boot.

That is absolutely not true. For example, use Microsoft's Media Creation Tool to create a Windows 10 USB flash drive on a legacy BIOS computer and the flash drive is bootable in both legacy BIOS (CSM) and UEFI modes (even with Secure Boot enabled).

Ah gotchas, i didnt realise they did that. Could be why i had some problems with it.
Im pretty sure a multi platform bootable ISO like that is only in the old MBR format and not GPT. GPT does have its bonuses.

What bonuses does GPT offer over MBR on a USB flash drive?

I dont think an mbr installation can fully run a 64bit installation of Windows properly, the partition table runs completely different. I used to get loads of recovery problems if i screwed something up from messing about.
GPT gives me the confidence. She always boots, even on messed about and screwed up Raid 0 systems which i have two.

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GPT will let you transfer a single raid0 config from one motherboard to another, no problem !