Change boot priority not to boot to the USB.
Sometimes, even without any boot option selected for USB device, the computer may still look for the USB device and run a complete scan before the boot will pass to the local HDD.
When comes to the USB issue, I would also suggest we install the latest mobo chipset driver, follow by a reboot.
The new chipset driver can help to correct most USB issue (software).
Hope this helps.
Tech Manager, WPTinc.