Ensure you have your Windows license key (though modern PCs usually have this embedded in the motherboard). Why You Can’t Format Drive C from Within Windows
Download the Windows Media Creation Tool from Microsoft’s website and create a bootable USB flash drive (at least 8GB). how to format drive c
Formatting erases everything, including viruses. However, the virus could be on other partitions (D:, E:) or in the boot sector (rare). Ensure you have your Windows license key (though