I recently acquired the above anti-virus for the low of sum of "FAR" (free-after-rebate), ie. I only paid the sales tax on it. This is a good program that performs well under Vista x64.
When I attempted an upgrade of one of my computers to Windows 7 RTM (final version), the installation program instructed me that KAV was incompatible with Windows 7. I was forced to uninstall it before proceeding with the upgrade to Windows 7. At the time of this writing, Kaspersky only has a beta program for Windows 7. I hope they will issue fixes soon, as Windows 7 final version has been available to developers for a month.