Question Best was to clean a hacked computer

[cb6731]

Hello,
I am pretty certain that my sons computer has been hacked. He is a teenager using it mainly for video games so I have no idea what crazy sites he's gone to or what he's downloaded that he shouldn't have. Recently one of his video game accounts was hacked and an email account. We have since added 2 factor authentication but continued to have issues which makes be believe the hacker must have access to the trusted computer. Malwarebytes found something in the registry that it deleted and it currently has McAfee that says its fine however we've gotten security notices with the email account since the antivirus scans. If the computer wasn't fairly new I would just scrap it so I don't have to worry but that is not an option. If I download the USB Windows 11 to reinstall the OS will it be 100% certain that the hacker cannot access the computer or is it possible that they loaded something in the BIOS or boot files that will come back? We currently have the computer powered off until this can be resolved. Thank you for your help.

 

[USAFRet]

Full wipe and reinstall, with known good install USB.

How To - Windows 10 clean install tutorial

If you are looking for the Windows 11 Clean install tutorial, you can find that here: Windows 11 Clean install tutorial (Click here) Otherwise, welcome to the Windows 10 Clean install tutorial This tutorial is intended to help you, step by step, to perform a clean install of Windows...

forums.tomshardware.com

How To - Windows 11 clean install tutorial

Windows 11 Clean install tutorial This tutorial is intended to help you, step by step, to perform a clean install of Windows 11, version 23H2 or newer but can be equally applied to earlier versions which may have some basic differences in the screens you see but will largely remain similar in...

forums.tomshardware.com

 

[cb6731]

Full wipe and reinstall, with known good install USB.

How To - Windows 10 clean install tutorial

If you are looking for the Windows 11 Clean install tutorial, you can find that here: Windows 11 Clean install tutorial (Click here) Otherwise, welcome to the Windows 10 Clean install tutorial This tutorial is intended to help you, step by step, to perform a clean install of Windows...

forums.tomshardware.com

How To - Windows 11 clean install tutorial

Windows 11 Clean install tutorial This tutorial is intended to help you, step by step, to perform a clean install of Windows 11, version 23H2 or newer but can be equally applied to earlier versions which may have some basic differences in the screens you see but will largely remain similar in...

forums.tomshardware.com

Thank you for your response. I downloaded the Windows 11 to USB but the computer does not recognize it. In BIOS my only boot options are Windows Boot, Onboard NIC (IPV4 PXE) and Onboard NIC (IPV6 PXE). I don't see any way to force it to read the USB. I disabled Windows Boot and it went into Support Assist and somehow eventually Install Windows 11 came up, but it was only seeing my USB as the partition available to install it on and did not see my hard drive. If I set BIOS back to windows boot it still boots fine. Any suggestions?

 

[punkncat]

Be aware that if network sharing was on and this infection is bad enough, or the son used other house computers then anything can/may also be infected. Where and how did you get the installer USB?