As I understand you've been troubled with the unpredicted clicks on your AIO computer and here are a few steps that you could do: Click here (let's start with the basics)
Normally the hard reset would fix this issue, in case it hasn't you may click here.
Please access the Bios screen using F10 during restart and check if the touch screen works properly if it doesn't it would be a hardware malfunction and you will need to contact HP Phone Support for further assistance.
Yesterday I checked several reported cases of automatic, repeated left clicks caused by any windows settings. All turned out negative. I also ran several virus scans to exclude this possibility. At last, I performed a full reset of windows. However, the problem persists.
Today, I tried the hard reset you mentioned: no improvement. I am willing to check the F10 option, but I need some more information about how to check if the touch screen functions properly. What exactly does that mean?