I have a USB drive (SanDisk SDCZ40-016G) that mounts in a way I've never seen before. When inserted, two items appear in Places -> Computer:


"SanDisk Ultra Backup: 16GB" contains my data, and "CD Drive: U3 System" contains a Windows executable. The part with the Windows executable doesn't look useful to me so I'd like to remove it. I used GParted to delete the only partition listed on the device and then I created and formatted a new partition:


Strangely, the "CD Drive" containing the Windows executable was perfectly intact after this operation.

What's going on?

  • 1
    I just hate that
    – Pitto
    Jul 11, 2011 at 16:49

6 Answers 6


The solution came from u3_tool (universe), which can:

  • uninstall the U3 software
  • reclaim the CD-ROM disk space
  • run on Ubuntu

I ran sudo u3-tool -p 0 /dev/sdb and then repartitioned the drive. Now it mounts like a "normal" USB drive.

  • 4
    OMG, it's possible to replace the virtual CD image??? I was thinking it was hardcoded in a ROM! What they were smoking at SanDisk?? In this way someone could place a virus and it would be ran on Windows with the autorun.inf!!! Crazy Jan 4, 2014 at 18:21
  • It looks like the SanDisk driver is actually two drivers inside one USB box. In other words when probed it reports two devices inside the USB thing. So linux finds them both and sets them both up. Note that the 2nd one is read only. The u3_tool is able to talk to the SanDisk device driver setup and tell it to disable the second device (by setting it's size to zero). Thanks very much for this solution! Jul 25, 2016 at 23:31
  • It also works on Windows. Neat.
    – cde
    May 16, 2017 at 22:31
  • 1
    Works perfectly! I think they smoked something very bad in SanDisk
    – AndreaCi
    Jun 11, 2017 at 8:13

U3 is proprietary software that SanDisk loads on it's USB drive. It runs in a partition you can't reformat, or really detect, and it'll likely always be there.

If you have a Windows machine you can run the Un-installer using the guide in the SanDisk KB.


U3 Uninstaller is windows only. Available here:


I know of no way to do this in Linux.

  • I have one of those disks too. The U3 uninstaller previously mentioned worked for me. However, I see no reason to get those drives anymore. It is just too bad that the actual space for the CDROM cannot be recovered as usual disk space.
    – jfmessier
    Sep 24, 2010 at 12:10

Okay, here's a way to remove it on Ubuntu. First if you don't have it, do to Ubuntu Software Centre and download the 'Wine Windows Program Loader' after the download go to: http://www.geekyjock.com/pages/blog/2006/05/remove-u3-software-from-your-usb-flash.html And download the removal software for U3 at the end of the blog. Run the removal software with Wine and you're good to go!


I ran into a similar problem, was unable to delete a small U3 partition on my sans disk cruzer USB pen drive. I tried doing so within windows disk utility and used diskpart from the run prompt. the following didnt work for me, the u3 partition which appeared as a CD on my computer could not be deleted: SD formatter 4 did not work either: http://www.pendrivelinux.com/restoring-your-usb-key-partition/

U3 tool wouldn't run for me at all on windows 7


the one at sourceforge

had luck through sans disk website: http://kb.sandisk.com/app/answers/detail/a_id/2550/~/removing%2Funinstalling-u3-launchpad-on-a-pc#method2

which can also be found on instructables


In Linux (for me) it appears as another disk. You might be able to format that part. Personally I will not recommend it in the odd case it stops up the device, but I doubt it would.

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