Virus in boot loader of SSD, M.2 possible fix?

Brant

So I have a MSI MAG Z490 Motherboard and a while ago I installed a Trojan so I reinstalled windows from a USB but the virus was still their trying to make me give it permissions. So I flashed the bios and uninstalled and reformatted my drives through the Window's installer, but I thought that after a few weeks I might have soothing because Bitdefender was skipping file directories durring system scans.

This time I uninstalled windows and wiped the drives but through secure erase on my motherboard, unplugged the drives and flashed my bios.

My question is were the actions I have taken so far be enough or do I need to do more. I have not reinstalled windows yet my computer is sitting as a flashed bios with no drives connected.

1. Buy a new drive M.2 drive for Window's to load on?
2. Upgrade PC buy a new Motherboard, CPU, RAM, CPU Cooler, and a M.2.