elvalid :
After messing around with everything on all posts across google and beyond, I found my issue was that in BIOS, USB 3.0 was enabled, and needed to be set to auto.
Recap:
New HP Spectre USB 3.0 only
Win7 bootable USB
Safe Boot Disabled
Legacy Disabled
USB 3.0 Changed from Enabled, to AUTO.
Hope this helps.
I am having this same problem and after trying different USB sticks, all the different USB ports 3.0 and 2.0, creating the bootable usb 4 different times I cannot resolve this problem and it still comes up with the CD/DVD drivers missing error.
I have changed the Legacy from Enabled to Disabled to Auto and this did not make a difference.
There is no option on my ASrock motherboard to change USB 3.0 setting from Enabled to Auto.
There do not seem to be any other helpful settings in the mobo settings that I can play with.
I have only used ImgBurn for the ISO creation, so I haven't tried any other software alternatives for this part of creating the USB.
I have noticed that my motherboard seems to be UEFI - is this the problem? When creating the bootable USB I originally used Rufus as advised by the Novatech staff which has different instructions for UEFI and BIOS setups (and I could not use the ISO I have for UEFI for some reason so could only try the BIOS version), however the second time round I used WinToFlash just in case it was the boot creator software that was the issue. WinToFlash does not specify whether your PC is using a BIOS or UEFI setup.
The PC is running an Intel Celeron 1.6GHz processor with 4GB RAM and is brand new today!
What else can I do apart from getting a CD drive? Are there any other solutions?