U3 is a technology used install boot software on thumb drives. Companies use this to ensure that some little application will get loaded or something when you plug their thumb drive into your Windows machine.
This can be a favorite move of vendors who give away thumb drives at conferences as swag. They want to launch their little demo app or whatever when you plug in the drive.
It can be very annoying.
I am trying to create a Win7 install thumb drive for my wife’s netbook and I have a great 4G thumb drive to hold the media. Unfortunately, my thumb drive had this U3 stuff on it and won’t work as a boot disc as long as that pesky software is on it.
The simple answer is this little utility: U3Uninstall.exe. After running this utility on the thumb drive I have a plain ole storage drive I can use as a Win7 bootable install disc.
…Or format it..
Actually, U3Uninstall.exe is the only way. Formating doesn’t disable the U3.