How to add Write Access on FAT32 USB drive?

Question

I'm at my wits end here. I installed the Windows OS on my USB drive in order to install Windows on a brand new PC; for some reason this installation failed.

Upon plugging in the USB to my (old) PC again a few days later, I see that I can't delete anything; write access is disabled.

I've tried the following:

formatting the device (which is obviously impossible due to readonly mode)
accessing via USB's properties and disabling read-only from the Security tab (security tab doesn't appear because it's FAT32)
access via CMD's diskpart (cleaning leads to I/O error, presumably due to no write access), and as for clearing the readonly attribute, console says it's successfully cleared it but listing the attributes again or accessing from file explorer, shows it's had no effect
Delete drive contents from Disk management (I/O error, presumably because of no write access)
I've also tried downloading software related to this in order to help, as I figured I'm not the first who's faced this problem, but what I found was either from sketchy sites or old software which doesn't work on Windows 11

My USB does not have a physical write-protect switch

Now to be clear the USB worked perfectly fine and has been working perfectly fine for years, it's only upon installing the Windows OS that this stuff happened. I can see all the files from the download inside the USB and can open them without a problem, so I don't think the device is corrupted.

How else can I add write access to this USB? It's a SanDisk Ultra.

The simplest way to solve this problem is to remove all of the partitions on the USB drive, and start over. You can do this on Linux using dd to blow away the master boot record, or do this on Windows using diskpart.. — mti2935, Jan 07 '24 at 07:35
What have you exactly tried running (which commands) with diskpart? — Sir Muffington, Jan 07 '24 at 13:52

score 0 · Answer 1 · answered Jan 07 '24 at 11:14

0

The FAT32 filesystem doesn't support control access aka ACL.

I can think of only these reasons why it's not writable:

It's physically dying/dead
It has inconsistencies (run chkdsk/disk check)
It has the read/write physical toggle

It's up to you to figure out which one of these applies to you.

Or you can simply try to reformat it.

answered Jan 07 '24 at 11:14

Artem S. Tashkinov

315

Question already said he can't reformat it. Very likely the USB disk has failed. Failing read only is a very typical failure mode and can be triggered by too many writes, especially on a drive that doesn't support write leveling. – user10489 Jan 07 '24 at 16:23

score 0 · Answer 2 · answered Jan 08 '24 at 14:54

If DISKPART CLEAN fails with an IO error this error is either caused by the stick itself (instead of just the FAT32 file-system) going read-only or the stick being totally unreadable. Since you can still read the old content the first case applies.

Some USB sticks will intentionally switch to read-only mode if their internal controller chips detects its storage is going bad.
If the controller catches this early enough the stick is still readable, but any further writes (even just updating the "last access" time-stamp on the files you are reading) may break the storage completely, so they are blocked.

So copy any data you still need (if there is any) to another location and then throw the stick away. The stick is broken and has become useless for data storage.

How to add Write Access on FAT32 USB drive?

2 Answers2