eblf2013 wrote:

Update
I think that installing a new harddrive, or shrinking the old Windows partition to make space for another OS, could also work. Should the malware autorun, a fresh installation of Windows or Linux wouldn't recognize the old installation's autorun (service) data, and the malware would not be able to plague your system immediately after its installation.
Only by inserting the installation disk while the system is off, then booting right into the installer, or by using a DVD/Blu-ray disc to install your OS, would it guarantee to work; A virus would be able to infect the files of a read-write medium (USB drive) if you insert it while the OS is running. (Even a Linux installer could be infected.)
Do not trust any program in your old partition/harddrive. A well-made virus could infect all of them.
(I assumed the BIOS couldn't be infected. BIOS infections aren't common nowadays.)