You know, well not always, you can afford to buy the best anti-virus out there to protect your PC. And not always the same anti-virus or anti-malware will stay in your PC. Consider a case when you do not have internet access to download free home edition of anti-virus but you have your USB drive with you and you want to scan a computer for infection and remove it using USB right away. Or lets say you do not want to install a heavy anti-virus software but you want to scan your PC at regular basis without installing any software. Here are some best portable tools which will remove Viruses, Malwares, Trojans and other number of infections from your PC without installing a thing in your PC. Portable antivirus will make complete virus scan possible using portable antivirus software.