I got a notebook from my sister. I wanted to download Steam there but my sister is one who clicked on almost every pop-up. Before I downloaded Steam because of VAC, I wanted to check it for cheats. How do I find out if there's anything on it or not?
Searching - but not easy, because cheats are often disguised as a simple program.
I would rather recommend that you simply reposition the box.
But you already know what cheats are, don't you? What do cheats have to do with pop-ups?
To find what you are looking for, you lack specialist knowledge and we do not have detailed information.
If you absolutely want to have a "clean" computer, then reinstall Windows is good.
I know but she also downloaded every nonsense
Let Sophos Hitman Pro or Emsisoft Emergency Kit run over it. The "cheats" are likely to be recognized as PUPs, potentially unwanted applications. If they were downloaded from popups, they are definitely viruses and should therefore be detected even more
I will now reinstall Windows 10. I selected delete everything. Could there still be a program in the background that is not deleted?
Unlikely.
If you delete all partitions, there's not much left where malware could "hide".
You start the setup from an external data medium. The Windows from the hard disk is then inactive at this moment.