TeamViewer issue

Question

Today I had the stupidity to grant full access to a stranger on my TeamViewer. Don't ask me why, such a foolish thing to do.
So once done, he/she created an admin account on my laptop and blocked my access. Now I cannot delete any programs as it requires a password, neither my browsing history, cannot do anything really. Tried to re-install the operating system, but still the same - needs a password. He must have been into BIOS I guess. I have disconnected the laptop from the Internet, so hopefully won't be able to do any more harm. He had access over 2 hours until I found out what was going on and God knows what things have been done during this time. Any suggestions what to do?

I have to access the created by him account somehow, delete it, delete TeamViewer and reinstall the OS. Would that be enough, though?

He probably knows my IP, all the logs, system info, registry etc., literally everything.

Answer 1

First of all, this is not a Teamviewer issue. Second of all, you did not tell us anything about your system details suchs as the operating system and if you're still able to boot from either USB or DVD.

For the sake of it, I'll assume you use Windows and can still boot from USB or DVD as I doubt this person was in the BIOS. I'd recommend to use ERD Commander or BART PE.

These discs contain tools to overwrite the Windows password file. Booting it will let you set a password for the administrative account. Once done, reboot and you'll have access again.

Backup all you data and perform a re-install of the operating system.