I've been reading about it because I had the same problem when trying to load 64 bit linux mint OS from an USB stick and it seems that it happens with Gigabyte motherboards... (I have Gigabyte GA-990XA-UD3) I found the solution here: http://forums.anandtech.com/showthread.php?t=2367766
Configure your BIOS with the following parameters: xHCI handoff - Enabled EHCI handoff - Enabled IOMMU controller - Enabled Regards. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1574869 Title: USB controllers are not recognized (live and install 16.04 Xenial) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1574869/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
