U3 (software)

U3 was a joint venture between SanDisk and M-Systems,[1] producing a proprietary method of launching Windows software from special USB flash drives. Flash drives adhering to the U3 specification are termed "U3 smart drives". U3 smart drives come preinstalled with the U3 Launchpad. Applications that 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.

Microsoft and SanDisk created a successor called StartKey.

SanDisk began phasing out support for U3 Technology in late 2009.[2]

U3 platform

U3 disk mounting: Hardware emulation

Criticism

Numerous criticisms have been made of the U3 platform. These criticisms are:

Malware-like integration behaviour: Software comes preinstalled on USB disk and, when using stock Windows settings, roots itself in the system similar to malware. U3 removal is possible, but requires complete data backup.

Questioned use: There are already portable versions of many Windows software available, some of which do not require any proprietary solution to work.

Removed user data, but not all of it: Recent files and programs had it listed.

Freezing with certain CD writing software: There is a possibility of slowing down or freezing Windows XP Pro if certain Windows drivers that are associated with high-volume data transfers to CD writers using certain CD/DVD burning software installed.[12]

Proprietary format/closed platform: The U3 platform is a "closed" platform / proprietary format. SanDisk, the rightsholders for U3, ask for a 5% royalty from USB flash drive manufacturers who wish to implement the platform on their products.

Two drive letters: As a work-around to the lack of Auto-Play for Flash drives on older versions of Windows, the U3 software creates two drive letters (one which presents itself as a CD to allow Windows' auto-play to start the launcher, and another for storing user data). Although this is the only way to implement auto-start functionality on pre-Windows XP systems, it could be considered a kludge, and the extra drive letter created can be an annoyance. However, it is possible to prevent Windows from allocating a drive letter for the "CD drive" via the Windows "Disk Management" tool—as long as the user has the appropriate rights/authority to do so.

Incompatibility with certain embedded systems: Some host systems—such as photo kiosks, consumer electronics, and other embedded computing devices—cannot correctly mount U3 "smart drives." The problem may arise because the emulated CD-ROM is the first drive presented to the host system. As such, the device is detected as a CD-ROM drive or not at all. Although some newer photo kiosks are U3 aware[13] and can overcome this limitation, it still exists on many platforms.

type	Private
foundation	2004
location	Redwood City, California
industry	Computer
homepage	(Defunct)

U3 platform

U3 disk mounting: Hardware emulation

U3 Launchpad

U3 applications

APIs

APIs

Compatibility

Issues with older versions

Developer resources

Removal

Criticism

See also

External links

References