That's because the S-ata controller isn't been picked up automatically. You require the controller drivers. They should be able to be obtained from the motherboard website. What board is it?
Are you trying the usb stick on the usb3 port, i had the same problem recently cant remember what i did, ended up connecting a dvd and installing via disk in the end i think
fixed!
fixed! dont use the front usb 3 ports! use the usb2 ones around the back!
thanks bradmax!