www.webroot.com http://www.amazon.com/Webroot-Secur...F1JK/ref=sr_1_1?ie=UTF8&qid=1334533834&sr=8-1 The best is actually Norton, but Norton is a resource hog. The next best is Webroot which uses cloud computing. Webroot is very fast and complete scan. It is named PC Magazine's antivirus of the year. Read the reviews and check it out. License for 3 PCs.