I tried installing Zorin 17.1 to a 500 Gb USB flash drive on both a 10 or 12 year old Dell Latitude E6430 laptop and a two year old Framework laptop. The results were as follows.
With a new Sandisk 400MB/s flash drive it took 4 or 5 hours to install Zorin 17.1 on the flash drive and then it would not boot on any of the three laptops I tried. I concluded that the flash drive was defective and returned it to Amazon.
With an older slower Sandisk flash drive I was able to install Zorin 17.1 and boot on the Framework laptop but the flash drive would not boot on the Dell. It said, "Invalid partition table."
With a new PNY 600MB/s I was not able to install either Zorin 17.1 or Mint 21.3 with either laptop. In all cases the installer said it was going to write the partition table to the disk and it might take a while and after about 3 hours it still had not completed that operation so I gave up.
I then used the same PNY drive with the Latitude laptop and was able to install Rhino Linux on it in about 30 minutes with no problems.
In all cases I booted the ISO to the laptops originally from a Ventoy USB drive.
Do you have any Secure Boot settings in the Dell; or any CSM / Legacy options?
With that old of hardware (not hating, got some pretty old stuff myself!), you may have some driver issues after install - but, I'm suspecting the invalid partition table is having to do with GPT and UEFI (newer boot / partition table layout). With the Dell, try using Unetbootin or Rufus and (in Rufus only) changing the UEFI option to MBR and writing the .ISO file again to the USB. Unetbootin writes an MBR style installer by default but needs to be FAT32 with the USB.
For the Framework laptop, instead of using an application to write the USB - format the USB in NTFS, then extract the whole contents of the .ISO file, hidden '.files' and all to the root of the USB, then try to boot and install from it. But, be aware - this method will only work with newer UEFI / EFI boot types; likely what the Framework has. The Dell, being a little older, needs an older boot type - MBR.. maybe..
Is that Dell a 32bit or 64bit architecture? 