What’s the best way to completely format my brother’s PC after malware issues?

Make sure to note down your Windows key first. Boot into BIOS and use the erase tool to wipe everything clean. Then, plug in your USB with the installation media and follow the prompts for a fresh install.

If the malware is particularly nasty, you might want to consider replacing the hard drive completely. Sometimes, the best option is to start from scratch with a new drive and a fresh install of Windows. Given the low cost of SSDs nowadays, it could save you a lot of time and hassle with malware residuals.

There's no real need to keep files if you want a clean slate. Just make sure to have the Windows installer on a USB drive and set your BIOS/UEFI to boot from it first. This way, you can delete partitions and start fresh. If malware is involved, opting for a fresh install rather than a reset is a safe choice.

Another option is to boot from a USB with an OS image. You can use the installation tools to delete existing partitions or just nuke them all and create new ones. This gives you full control over how the drive is set up.

To completely wipe your PC and start fresh, you'll want to create a bootable USB drive using the Media Creation Tool. This allows you to format your drive entirely before reinstalling Windows. It’s the best way to ensure all traces of malware are gone, especially if you suspect serious infections. Look up guides specific to your version of Windows for detailed steps on the process!