How do I remove hidden user

Have an Aspire one that came with Win 7. Listened to MS and did the "Upgrade" to Win 10. Been living with an ongoing problem of a user "Jeffrey" that was on the PC before we obtained it.

When I turn on the PC Jeffrey pops up as initial user but we don't have the password so have to select a second user.

Have been working trying to deactivate or delete Jeffrey but the Command net user does not show a user with that name.

I have traced down in Registry under Winlogon this user but still have no way to remove this user.

Even did a computer reset but that didn't delete this hidden user.

Really want to clean up the Win 10 OS so have created a boot USB stick. but am hesitant to attempt a clean install as I am reading of others having issues with attempting clean install of Win 10 but loosing the Key or having activation problems.

I really don't want to simply delete the key Winlogon as I don't know what else needs this info.

Jeffrey seems to be related to the domain Acer-PC so am thinking that Jeffrey is something Acer is responsible for.

 How do I remove Jeffrey so I don't have to click past him every time I start the PC?

Note the NEITHER user aCER-pc OR jEFFREY SHOW UP WHEN i RUN COMMAND NET USER so normal commands will nto work.