Dr.Web LiveUSB offers you a USB to clean up your PC in case of virus attack. It runs from a USB stick (no installation is required), performs a thorough scan of your disks and directories, detects all types of infections (keyloggers, dialers, spyware, adware, etc.) and removes them from your computer. Dr.Web LiveUSB is a very effective alternative for live CD. It is a freeware and compatible with Windows 2000/XP/Vista and 7.