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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?

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I just hate that – Pitto Jul 11 '11 at 16:49
up vote 21 down vote accepted

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.

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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 – Magnetic_dud Jan 4 '14 at 18:21

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.

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U3 Uninstaller is windows only. Available here:

I know of no way to do this in Linux.

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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 '10 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: 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!

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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:

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


the one at sourceforge

had luck through sans disk website:

which can also be found on instructables

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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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