So I built a new system, and created a bootable USB with Win7 on it, I've tested it on my previous comp to make sure it is bootable.
I plug it into my USB slot (tried both USB 2 and 3 slots) and set the bios (F15) to boot from what it reads as a Generic Storage Device 0204
I reboot and then see "Press any key to boot from USB..." <-- 3 dots which immediately (<1sec) changes to 4 dots. And then the system hangs. Num and CAPS are both lit up, and cannot be turned off. Nothing else does anything.
While I'm in the BIOS, the keyboard functions just fine. It's a USB keyboard plugged into a USB 2.0 slot (but also didnt work when plugged into a USB 3)