Windows 10 bootable USB has 2 UEFI patitions?

Apologies if this is the incorrect forum for this but I was unsure where best to post this.

I've created a Windows 10 bootable USB using Rufus in order to do a clean install of Windows but when accessing the Windows boot menu I have multiple options to choose from and was unsure which one to select.

KingstonDataTraveler 3.0
UEFI: KingstonDataTraveler 3.0, Partition 1
UEFI: KingstonDataTraveler 3.0, Partition 2

Unless I'm mistaken I know the "KingstonDataTraveler 3.0" option is for legacy support i.e. systems using BIOS appose to UEFI but which UEFI partition do I choose?

The bigger question is why did you use Rufus? We would have to see a screenshot of disk management, or other partition program to see what partitions on the USB flash drive Rufus created.

That flash drive needs to be MBR partitioned with a single FAT32 partition marked as active on it.

Hi NavyLCDR

I'm using Rufus because using the Windows media creation tool to create a bootable USB always fails with some seeminly generic error message and the iso downloaded through the media creation tool doesn't have a matching checksum to any know release for some reason.

I was following this guide on Windows Central.

Here's what Disk Management looks like.

It's highly unlikely that the USB flash drive will boot in UEFI mode. Most computers will only boot in UEFI mode from a FAT32 partition. What is really strange is in the list of volumes, there is an E: drive "UEFI_NTFS" with a 0 byte size.

I would suggest you make a common Windows 10 installation USB flash drive instead of whatever crazy format Rufus created. In a command prompt (Admin) run:

diskpart
list disk
select disk # <-replace the # with the actual number for the USB flash drive
clean <- this will erase the drive selected above, make sure it is the USB flash drive!
create part pri
format fs=fat32 quick
active
assign letter=u
exit
exit

Then mount the Windows 10 ISO file. In Windows 8 and 10 you can mount an ISO file directly in file explorer. Then copy all the files and folders from the mounted ISO file to the USB flash Drive (U:). Now you have the standard Windows 10 installation USB flash drive that will boot in either a legacy BIOS or UEFI computer.

I followed the instructions you gave but after mounting the ISO and attempting to copy the files to the USB I receive the following dialogue box.


Not that it really matters now since I tried creating a bootable USB using the windows media creation tool and it decided to work this time!

Thanks anyway NavyLCDR (No sarcasm intended).

Here's some information regarding the "UEFI_NTFS" drive if your curious.
https://github.com/pbatard/uefi-ntfs

Finally this is what my boot options look like now,

and just to clarify I should select the"UEFI: KingstonDataTraveler 3.0, Partition 1" option correct?

Yes. UEFI is the option you want.

D3SOL4TE said:

I'm using Rufus because using the Windows media creation tool to create a bootable USB always fails with some seeminly generic error message and the iso downloaded through the media creation tool doesn't have a matching checksum to any know release for some reason.

The MCT fails because the USB you gave it had a gpt partition layout....

Bree said:

..I have now confirmed that the Media Creation Tool fails with error code 0x80004005 - 0xA001A if the USB you ask it to use has a gpt partition. This is usually due to having use Rufus to format the USB previously.

Media Creation Tool Error Code 0x80042405-0xa001a - Windows 10 Forums


The reason there is no chechsum available is that the MCT doesn't actually download an ISO, what it downloads are the compoenents to contruct an ISO, meaning that each one will have a different checksum depending on precicesly which options you chose (eg 32-bit, 64-bit, or both). Even making the same ISO twice in a row with the MCT can result in each nominally identical ISO having a different checksum.

D3SOL4TE said:

I followed the instructions you gave but after mounting the ISO and attempting to copy the files to the USB I receive the following dialogue box...

When you download an ISO direct from Microsoft it will contain an install.wim. When you make an ISO with the MCT it will download an install.esd to put into the ISO. Fat32 has a 4GB maximum file size limit. An install.esd is more compressed than an install.wim and will always be smaller than 4GB.

NavyLCDR said:

Yes. UEFI is the option you want.

Thanks.

Bree said:

The MCT fails because the USB you gave it had a gpt partition layout....

Media Creation Tool Error Code 0x80042405-0xa001a - Windows 10 Forums

I'm pretty certain I had tried it with a MBR partition also but it would previously still progress so far but then fail with an error message.

Bree said:

The reason there is no chechsum available is that the MCT doesn't actually download an ISO, what it downloads are the compoenents to contruct an ISO, meaning that each one will have a different checksum depending on precicesly which options you chose (eg 32-bit, 64-bit, or both). Even making the same ISO twice in a row with the MCT can result in each nominally identical ISO having a different checksum.

When you download an ISO direct from Microsoft it will contain an install.wim. When you make an ISO with the MCT it will download an install.esd to put into the ISO. Fat32 has a 4GB maximum file size limit. An install.esd is more compressed than an install.wim and will always be smaller than 4GB.

Thanks for taking the time to explain I appreciate it.

Hi Rufus developer here.

NavyLCDR said:

It's highly unlikely that the USB flash drive will boot in UEFI mode. Most computers will only boot in UEFI mode from a FAT32 partition.

That's a very common misconception. However, this is inaccurate as explained at length in the Rufus FAQ.

Any UEFI computer can be made to boot from an NTFS partition and in fact, the reason why you see 2 partitions in the drive created by Rufus is because:

1. The latest Windows retail ISOs contain a file that is larger than 4 GB, therefore FAT32 cannot be used as is
2. Rufus is designed to work around that issue by automatically installing an NTFS UEFI driver during boot, if needed, so that UEFI systems that don't already have provision for NTFS boot (which is becoming more and more common by the way), can also boot the NTFS partition with the 4GB file in pure UEFI mode. See here for details.

What is really strange is in the list of volumes, there is an E: drive "UEFI_NTFS" with a 0 byte size.

That's just Windows not properly reporting that the UEFI:NTFS is 512KB in size (not 0). This is the FAT partition that contains the UEFI NTFS driver and bootloader used by Rufus.

OP, have you actually tried booting the partitions you saw? I got a strong suspicion that your UEFI firmware already contains an UEFI NTFS driver (else it would only allow you to select one partition) and either one should have allowed you to boot and install Windows, even as the drive was formatted with NTFS.

One thing you may have to do for UEFI:NTFS to work is temporarily disable Secure Boot (but if you are concerned about temporarily doing so, please read this other FAQ entry), but apart from that, there was nothing wrong in the options that were presented to you during boot, and in fact, I fully expect that, if you had simply tried, you would have found that they worked as expected to let you install Windows (as opposed to jumping through hoops to use FAT32 when your original ISO contains a >4GB install.wim).

Thanks for the reply Akeo.

I think I tried booting from "Partition 1" and while it appeared to work I wasn't sure if it would cause any issues?

For future reference providing it will even boot to begin with does it actually make any difference whether I boot from Partition 1 or 2?