does it work with USBs? in the free version

Does the free version of Recuva work with USBs?

Usb flash memory/SSD or usb hard drive? Generally, recuva will work on both; however, because of the way flash memory and SSDs work, recovery (from any program) can be hit-or-miss.

error message is: unable to determine file system type - the other free "download" recovery programs says I have a lost partition

It will work but needs a valid partition and file system to do so at least in Windows.

So Recuva wont work then on a flash memory USB

Yes, Recuva works on flash drives. But the question is does Recuva work with USB attached devices?

In my experience Recuva works fine in all functions with flash drives directly plugged into a USB port, and with HDD's accessed via a USB attached caddy.

So yes, Recuva works with USB attached drives. But from your second post I don't think that that is the problem, the device seems corrupted, which Recuva won't cure.

I see - I have used EaseUS and Stellar - thy are ableto get to thefiles on the USB. However it is very expensive to use either one of those, especially as it is a once-off and I don't think I need the year's subscription

Some recovery tools require a valid file system to recover files especially the freeware variety which is why people not wanting to spend 1 cent on such a tool may do a quick format on a drive/disk to allow such a tool to function - but there's always the risk of destroying the files you need to recover doing that. Whereas other recovery tools may cost money (sometimes allot of money) that can recover from drives/disks that are deemed as unformatted in Windows.

Thank you all - it seems my choices are pay for either EaseUS or Stellar as they start the process and obviously get past the lost partition. I am not sure how much of my USB would be recoverable and pay about $100.

or

format the disk and see if Recuva can recover the deleted files - but there is a limit of ?? (MB) - how many MB Recuva will recover for free?

There's no data limit on Recuva free or paid.

There are still some unresolved questions, is this a flash drive or an USB attached SSD? What version of Windows are you on?

If it's an SSD and you are on a late version of Widows then I believe TRIM is, or can be, propogated across the USB connection, and a format with TRIM will wipe the device completely. But don't ask me to confirm this, as I can't.

If it's a flash drive (i.e. a flash device plugged directly into the USB port) I don't think that TRIM will be in effect. But again I can't confirm that.

3 hours ago, Augeas said:
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		If it's a flash drive (i.e. a flash device plugged directly into the USB port) I don't think that TRIM will be in effect. But again I can't confirm that.
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USB flash drives ("UFD") would have to be formatted as NTFS for Trim to work however it won't work, and NTFS is not a typical file system for someone to be using on a UFD unless the capacity was over 32GB.

This is what I get when invoking Trim via a command prompt on one formatted as NTFS, i.e.; Win10 or the flash controller itself doesn't allow it:

"The operation requested is not supported by the hardware backing the volume. (0x8900002A)"

But then on the other hand there are USB solid state flash drives, I've seen them as MLC and TLC, and those I'd imagine should support Trim since they're essentially just an SSD anyways, but those would be rare for most people to own due to the cost being significantly higher than a standard 2.5in SATA SSD of the same capacity.

I was thinking more about whether the USB software supported the TRIM command. TRIM is a SATA command, and USB protocal isn't. I have read that later USB software can support TRIM, but it's all a bit hazy. TRIM is becoming less relevant now, as the trend in SSDs is towards foreground garbage collection.