Because of the number of files on modern machines, especially PCs running any semi-recent version of Windows, a full scan is going to take a while no matter what you do. Especially if you have any number of software titles installed. It's speed will always be limited to the speed of your hard drive(s). But, IMO, McAfee VirusScan is the way to go. I use it on my machine at home (PIII, Win2K, 7200rpm drive, 512MB RAM), and I have no complaints about use of resources.