Yes, I followed the directions for a hard reset from the HTC support site (https://support.htc.com/en-uk/005-HTC_One/0A0/030/010
). It is more like it reset it back to a certain point last evening, but not all the way to factory settings.
I was hoping to avoid the store, but I am starting to come to the same conclusion that I probably just need to start from scratch again with a new phone.
Thank you for the quick response.