Greetings,
Welcome to the forum.
I am not a HP employee.
Have been messing with PCs since the mid 1980s. Never saw this one before.
You see a perfectly formed, red circle from the POST to a successful operating system startup. You then see a circle in everything you do within Windows. Is this circle fixed at one point on your display or does it move around?
Contact HP (Link) if you are in warranty.
Have a local PC tech take a look.
Regards