Does a factory reset remove all viruses? In Android it is different
Even if we have antivirus software installed on our computer, there is always a small chance that, if we are not careful, we will end up getting infected with a virus. When this happens is when the headache starts. Modern viruses have replication functions that allow them, even if they are deleted, to reappear after a while. So how can we properly remove a virus from our computer?
The most natural thing is that we resort to formatting the device. Resetting the computer to factory settings, in general, is erasing the entire hard drive and all its partitions and reinstalling the operating system from scratch, in this case Windows. In this way, what we achieve is to have a clean installation of the operating system, without any trace of the virus that infected our computer. The virus may remain on another hard drive, or on a flash drive, so we must be careful.
However, not everyone has the knowledge to know how to format a computer, reinstall Windows and configure everything from scratch. That's why Microsoft has included a function called "Reset your PC" in its operating system. Thanks to it, we can leave the computer as new from the factory without having to do anything at all. We can also keep our data if we don't have a place to store it.
But does the PC reset function remove all viruses from your computer?
- Resetting your computer removes "almost" all viruses.
When we usually choose to reset our PC, what Windows does is return the system state to its original state. It will remove all drivers, all programs, all processes, services, and files… and when everything is deleted, it moves on to reinstall the system. We also have the option to take advantage of the reinstallation process, download a new ISO image of Windows from Microsoft servers, and install it on the computer to update it.
By removing everything that does not come by default with Windows, viruses usually disappear. It does not matter where they are installed and hidden: in the form of a DLL file, a driver, a program, a process, a service... With the exception of very advanced threats, which we certainly rarely encounter, all viruses, Trojans, and other threats disappear after restoring the system to its original state.
Viruses that usually survive a factory reset are Android viruses, as they are installed in the system partition with root permissions. However, on Windows, it is almost impossible for them to do so.
- My computer is still infected with viruses even after formatting it. Why?
If we still have an infected computer after resetting the computer to factory settings, it is not because the virus remains, but for some reason, it has been reinstalled into the system. This can be due to several reasons, the most common of which are:
We have reinstalled malware.
The virus was hiding in a backup, and we accidentally restored it.
- The malware was located in another partition of the system (if we have multiple hard drives) or in a flash drive that we connected to the computer.
- There is another infected computer on the network, and when it is connected to the Wi-Fi network through a mobile virus, it infects our computer.
It could also be that we have malware at the BIOS/UEFI level. These programs, called rootkits or bootkits, are more advanced and complex to remove.