Unable to read FAT32 formatted drive in Windows 10

Question

My Dell XPS13 notebook will not read any FAT32 formatted drive, be it a USB flash drive or the bootable UEFI partition.

This is preventing me from:

Updating Windows 10
Entering Safe Mode
Reading any FAT32 drive
Re-installing windows

I've tried both UEFI (Secure Boot) and Legacy boot.

The screenshot below shows a known good 4GB, properly formatted FAT32 USB stick. EaseUS Partition Master recognizes as FAT32, Windows 10 Disk Management sees it as RAW.Partition Master however cannot read the disk contents. If I try to re-format the drive (or smaller drives) to FAT32, it fails.

Please !!! This computer will not read any FAT32 drive, USB, internal or external. The drives I try are all correctly formatted, and readable. I plug in a known, good drive, and the computer reports that it needs to be formatted. Trying to reformat to NTFS works fine, but a format to FAT32 fails, and the machine wants to format it again... etc etc.

I cannot re-install windows: because, All Windows 7/8/8.1/10 installation ISO files are designed to be extracted to FAT32.

Seems like a driver problem, but i dont know where the FAT32 drivers are ? Does anyone know?

What do updating windows, safe boot mode and reading FAT32 have in common? — davidbaumann, Nov 02 '19 at 17:33
Whare are the drivers for fat32? Are they in the bios, or Windows? What is broken that is causing any fat32 drive not to be readble. Another thing I notice is that every time the laptop boots up, there flashes up a warning.. scanning drives .... Repairing drives. — Martin Lintzgy, Nov 06 '19 at 00:30
@MartinLintzgy Are you cancelling the disk check during Windows boot up? If you're getting that every time you boot Windows, one of the drives likely has a hardware error (likely the USB drive). If the USB drive isn't plugged in during boot, do you still get a disk check at boot? (Windows natively supports FAT32) — JW0914, Nov 08 '19 at 13:27
All Windows 7/8/8.1/10 installation ISO files are designed to be extracted to FAT32. that's simply not true. All Windows installation disks since at least Vista can boot from an NTFS drive without problem. You've probably used the wrong tool to create the installation disk — phuclv, Nov 28 '19 at 16:01
How?? The bootable re-install drive always is FAT32, which i cant boot off :-( — Martin Lintzgy, Nov 30 '19 at 13:54

score 5 · Answer 1 · answered Nov 02 '19 at 13:57

5

It is possible that your windows might not be assigning letters to the drives properly. You should open run (windows + R), and then type 'diskmgmt.msc'. If you can view your drive there, just simply assign a letter to drive by right clicking on the partition of your usb drive and assigning it a letter.

answered Nov 02 '19 at 13:57

Bhavya Gupta

447

If I do a ms config, on the boot tab, there is no bootable uefi media showing, and the safe boot checkbox cannot be selected. – Martin Lintzgy Nov 06 '19 at 00:36
Probably you have selected legacy only mode in bios.. – Bhavya Gupta Nov 07 '19 at 09:44
Incredulous that it worked for my issue. Thank you. It puzzles me why would Windows not assign a drive letter to a drive so you can access normally? – midnightBlue Aug 12 '22 at 09:42

JW0914 · Answer 2 · 2019-11-08T13:23:08.530

2

All Windows versions recognize FAT32, so it's likely its partition was created, but never formatted, else an error occurred during formatting or the drive is failing.

How is Windows able to boot if it doesn't recognize the EFI partition?
(Disk Manager shows the EFI partition is recognized... it's partition 1 on disk 0)

Try formatting the USB Drive via DiskPart:

WinKey+R
Open: DiskPart
1. lis dis
  - Ensure USB drive is Disk 1, else update #2 accordingly
2. sel dis 1
3. clean
4. convert mbr
5. cre par pri offset=1024
6. format fs=fat32 Label=BUSBI
7. assign letter=D

If this results with the drive still not having its filesystem recognized by Windows, the USB drive has a hardware issue and should be replaced.

edited Nov 08 '19 at 13:23

answered Nov 08 '19 at 13:15

JW0914

7,865

This is not a linux machine, and of course i wait for disk check to complete. the reason why windows update always fails is Error 0x800703ed The error 0x800703ed means ERROR_UNRECOGNIZED_VOLUME: // // MessageId: ERROR_UNRECOGNIZED_VOLUME // // MessageText: // // The volume does not contain a recognized file system. // Please make sure that all required file system drivers are loaded and that the volume is not corrupted. // #define ERROR_UNRECOGNIZED_VOLUME 1005L .. and around in circles, because the unrecognized volume is the FAT32 formatted EFI drive. – Martin Lintzgy Nov 30 '19 at 11:13
And around in circles, because the unrecognized volume is the FAT32 formatted EFI drive. I think the driver is called Fastfat.sys, but how to install? i can only guess that it got corrupted or perhaps the ssd drive has a bad memory element? – Martin Lintzgy Nov 30 '19 at 11:21
just attempted to create a Re-install ISO from https://www.microsoft.com/en-gb/software-download/windows10 on to a flash drive. I formatted it to NTFS. The installer re-formatted to FAT32, useless. – Martin Lintzgy Nov 30 '19 at 13:52
@MartinLintzgy It would prove immensely helpful to you to simply to google this or search StackExchange, as this can be found within the first few links returned. The Media Creation Tool will format a USB as FAT32 to enable installing to a BIOS or UEFI system, and if you'd like to use NTFS, try Rufus; however there's no point using NTFS for a WIndows install USB, so I'm perplexed as to what the issue exactly is? – JW0914 Nov 30 '19 at 15:14
thank you for trying to help, JW0914 I have searched how yo install a windows ISO that is bootable from NTFS. I have found none. Rufus, as far as i can tell supports up to Windows 7. Could you please help by sending a link? – Martin Lintzgy Nov 30 '19 at 20:21
@MartinLintzgy I included the link in my last comment... the download link is at the bottom of Rufus' main page (v3.8, last updated 2019.09.16). – JW0914 Dec 01 '19 at 01:46
I went on to microsoft web site, and downloaded windows10 ISO. I created a bootable NTFS drive using Rufus, and oladed the win10 ISO on to the bootable USB, following the guideline i found HERE. https://www.youtube.com/watch?v=_lrmZo_jXLA I went into the BIOS, and changed options to allow booting from USB. Booted from USB, offered to re-install windows, then failed – Martin Lintzgy Dec 01 '19 at 11:53
"The upgrade option isnt available if you start your computer using windows installation media" – Martin Lintzgy Dec 01 '19 at 12:00
@MartinLintzgy Right... if you want to do a repair install, you need to run the Windows Setup setup.exe while booted to Windows; if you want to clean install, then you'll install Windows by booting to the Windows install media. – JW0914 Dec 01 '19 at 13:28
dear – JW0914 I really appreciate the help! I ran the windows setup (repair) from the bootable drive, it started the repair, then failed. :-(
Throughout this whole fiasco, i have kept a log of various screengrabs. I will share it with you in case anyone gets any bright ideas.

https://drive.google.com/file/d/1NQDWaihq6SPeTO2-hmGVRa8-_jdpRYUf/view?usp=sharing
– Martin Lintzgy Dec 01 '19 at 20:30
i though i screen grabbed the final fail message. It reported that my (windows 10) machine could not be determined if it could run windows 10
https://drive.google.com/file/d/1vgxqOxIpt5n4H-RSo3zL57yaiFA7hzUi/view?usp=sharing
– Martin Lintzgy Dec 01 '19 at 20:40
"Sorry, were having trouble determining if your PC can run Windows 10. Please try again" – Martin Lintzgy Dec 01 '19 at 20:55
@MartinLintzgy Please use a Windows forum then for troubleshooting, such as TenForums, Windows 10 Forums, or Windows Forum – JW0914 Dec 02 '19 at 14:16
This can lead people in the wrong direction. It happened to me the second time that Windows stops recognising any kind of FAT. Whether it is FAT32 or FAT16 - Windows 10 simply refuses to recognise it. It is NOT a hardware failure. Last time Windows 10 was re-installed all the storage media formatted in FAT32 suddenly got recognised again. So it's NOT a hardware fault. It's a Windows 10 fault. – Akito Sep 25 '21 at 21:44
@Akito Your experience isn't the norm, but if the OS itself was the issue, performing the steps in this answer would fix the issue, else it's third-party software or hardware related. – JW0914 Oct 14 '21 at 12:11
@JW0914 Shorty after writing my comment I confirmed a 100% it is a Windows issue. The steps shown in the link your provided never helped. It is related to Windows loading the wrong Windows support partition(s) (not sure which one exactly is the actual one making trouble). After removing the partitions from the PC, everything started working again. So, again, I have proven it is 100% a Windows related issue. The issue is also 100% reproducible. – Akito Oct 15 '21 at 14:37
@Akito Fascinating - I'll edit my answer, adding the information you've provided, but please first reply back with what the partition type [MBR | GPT] is via: WinKey+R → DiskPart → OK → Lis Vol → Sel Vol # → det par → Type: – JW0914 Oct 19 '21 at 12:28

score 0 · Answer 3 · answered Oct 15 '21 at 14:52

For finding the solution quickly, read the bold text.

There are lots of comments and explanations regarding this problem around the internet. However, if none of them work for you, and you already DISMed and SFCed the crap out of your Windows, then this is the answer for you.

You need to make sure that your Windows does not use the wrong support partitions. If you have e.g. more than a single hard drive installed in your computer and you re-installed Windows a couple of times already, then it may happen, that at one point Windows installed its secondary partitions to the wrong drive. So, when you re-install Windows, the new Windows may refer to the wrong partitions and this is exactly what is causing this issue.

If you remove the non-fitting partitions or the entire storage media having the non-fitting partitions, then your Windows 10 will start to recognise all FAT16 and FAT32 storage media, as it should, immediately after a reboot.

You may rest assured, that all the solutions implicating that your Windows "must" be corrupted in such way are simply not correct in your specific case, especially if you are finding this answer as a last resort. This issue can happen without any corruption or similar 3rd party issue -- like e.g. hardware problems or 3rd party drivers -- whatsoever.

To be clear:
Before you manually remove any partitions from your main drive with Windows on it, you should create a full backup of the entire drive!

Unable to read FAT32 formatted drive in Windows 10

3 Answers3