[ @Peter Blaise],
Good to see you over here as well. Not sure whether this relates to your comment, but a couple years back I had the supposedly portable version of ‘Audials One’ (a BIG, swiss-army-knife multimedia program of theirs) installed to a bootable flashdrive. Nevertheless, it insisted on regularly writing a bunch of stuff onto the Windows boot drive, the Registry included — the whole point of what you seek to avoid by going the “portable” route — and doing various other unwanted, intrusive actions the details of which I no longer recall. So, I decided that this was a program I did not need, uninstalling all traces of it that I could find, and re-purposing that flashdrive. I have not had any adventures with any of their software ever since. They do seem to have a major name in this field, though I’m not in any position to say ‘Why’.