Download AVG Anti-Virus Pro for free
For example, the free version only lets you schedule a single virus database update per day, and one computer scan a day. You can schedule multiple events with the Pro version. You also get higher speed downloads with the Pro version.
AVG Pro usually goes for $29.95, but Computeract!ve is giving away free licensed copies through Jan 17, 2008. Good luck getting their download link to work, but fortunately CyberNet has pointed us to a couple of mirrors.