Lisa, thanks for the information you gave me, but I only managed to find two out of the four items I had to find in my BIOS. One was the secure boot which I had already mentioned, and the other was the TPM. I found it, and did a practice run to see if I could disable it. No problem, so I returned it to enabled again. So on this computer which I'm using at the moment, namely a HP laptop only about two months old, I could not find any mention of the ACHI function or the IDE mode for the drive. Perhaps those functions are only included in older computers?
I have spent quite a bit of time over the last three years dabbling with this Windows To Go project and now I think it might be time to give it away. If I did have a working flash drive with it in my pocket, and say I went to my place of work or to a friend's house where the situation arose where I wanted to use it. Can you imagine the reaction I would probably get if I told my boss or friend that I had to go into their computer's BIOS and make four changes there so I could enable my flash drive to run their computer!
Perhaps the best way to have a Windows To Go device with you while mobile, is to just purchase a small laptop computer with say a ten inch screen and carry that in your suitcase or briefcase.