You can actually have Windows Defender (or a few 3rd party AV) scan your pc at boot, without even starting safe mode or standard windows.
Turn on pc
Directly after post, in the same place you'd normally start mashing the DEL key for bios, instead mash either F5 or F8. This'll bring up the boot options menu. It's here you choose Command line with networking which leaves you with the 'C:/' prompt. From there, follow the AV direction of the one you use. At this interruption, windows is not loaded, nothing is loaded except for the driver files, so no exe's have yet been started. What you are doing is jumping into the actual pc before windows, so any virus except a root virus has not yet been started.
Hot plugging needs usually to be allowed (default is off) in bios, but essentially it's adding a hdd to a pc, while the pc is on and running. With the OS being loaded on your hdd, if you add it to another pc, it'll try and boot from both, so you have to pick the OS that's definitely not yours, and hope that Windows doesn't include anything from your hdd. Hot plugging gets around all that, windows being already up and running, so adding your hdd is no different than adding a USB device. Just don't open it, leave it closed, use the Antivirus to scan it as is.
Barring all that, last option is wipe everything, do a secure format (overwrites everything with a bunch of 1's, sometimes called a military format) and then delete the partition. Reinstall Windows. There isn't a virus made that'll survive all that.