4 Answers Sorted by: 19 First of all, USB means Universal Serial Bus. It is a standard for a control and data bus, just like PCIe, PCI, EISA and ISA are all buses. USB is not a device, like a CD or DVD drive. (Optical drives typically use SATA or IDE buses with the ATA protocol.) You would need to get the flash drive formmatted as a floppy again (FDD) or try selecting that option in the BIOS. Note that most current computers don't use the "USB ###" type options (FDD, HDD, ZIP, etc.). Instead, they recongize the flash drive as a hard drive device. USB-FDD "Unsupported" In summary: Generally speaking, if your system BIOS supports the USB-HDD boot option, it should boot Linux from a large capacity USB flash drive. (a BIOS that supports USB-HDD automatically detects the geometry of the USB Flash drive) What is the difference between USB CD and USB FDD? Only the option that includes the word “USB” is a USB option. FDD is a floppy disc drive, CD ROM is a CD drive, and HDD is a hard drive. How do I boot from USB FDD? Go into the BIOS, and go to the page that determines the boot order. aJoS.

usb cd vs usb fdd