Need to confirm the following information:
Board is provided: a Legacy (traditional BIOS) or state UEFI?Secure Boot (Safe Boot) whether the option is turned on?
U disk system supports UEFI boot or Legacy (traditional BIOS) boot?
Step follows a step troubleshooting.
1, no problem in the USB port, plug in the U disk, listen to what the speaker has no sound bite sound.What if a sound was heard, the computer did not recognize a USB device is plugged, it may be bad U disk.
2, if there is sound, indicating that can detect the USB device, the problem may not lead to the identification system.Operation can be as follows:
1) Right-point computer, properties, Device Manager, Disk Manager.
2) If a yellow exclamation mark devices, right-click on it to uninstall it.
3) If there is marked down arrow black disk, it is to be disabled, right-click it to start.Then refresh or restart the computer, generally found.
4) If the device manager no problem, and that is not automatically assign a drive letter.Right Computer (or My Computer), management, disk management. To find the change disk partition, right-click on it and choose "Change Drive Letter and Paths" and then choose "Add", you can assign a drive letter.
If not possible, that is, U disk is broken, damaged or system-related functions.To try to judge someone else''s computer
BIOS, set the startup items when you can not find the U disk?
cmos which need to set up
Clear the BIOS.