Formatting USB partition with CDFS

From the Wikipedia article on U3:

U3 is a company producing a proprietary method of auto-launching applications from specially formatted USB flash drives. Flash drives adhering to the U3 specification are termed "U3 smart drives". U3 smart drives come preinstalled with the U3 Launchpad, which looks similar to the Windows OS start menu and controls program installation. The method works with recent Microsoft Windows systems only. Applications which comply with U3 specifications are allowed to write files or registry information to the host computer, but they must remove this information when the flash drive is ejected. Customizations and settings are instead stored with the application on the flash drive.

I don't personally use the U3 software, but some less technologically-inclined people in my office appreciate having the file management built into their flash drive. You can also install portable applications onto the drive, but again, I find it easier to maintain my flash drives myself and use http://portableapps.com/.

Some USB sticks can be configured to present themselves as two or three storage devices. This works at firmware level – instead of a single disk with partitions, the OS sees two or three separate devices, so you cannot just repartition it.

(U3 is just one example. Another manufacturer, the name of which I forget, sells USB sticks with a ~200 MB read-only partition holding ~20 MB of promo JPEGs and Kaspersky trialware.)

You need special software to reconfigure the drive. Unfortunately, most such programs are Windows-only, not officially available to the public, and you have to know the flash controller being used inside your USB stick and find the specific program.

• Tools for U3 drives are widely available.
• UT165 – I have used this myself to remove the aforementioned Kaspersky junkware, seems like a common controller type.
• iCreate

^{if anyone has programs for other types, feel free to add.}