Famous malware (virus) threats such as Conficker have the ability to spread using removable devices by making their own DLL and autorun.inf files that will help them to infect any device that offers USB connectivity. Therefore, it doesn't matter if you reinstall your operating system - if your antivirus doesn't recognize the virus on the infected USB device, once you plug-in the USB - you will get the virus. The current version runs on almost all versions of Microsoft Windows such as XP, Vista, 7 and 8.