I believe it is fairly large - perhaps 40 to 50 megabytes for a full fresh install, maybe even a bit more. Once installed, the regular updates for the firewall rules and antimalware signatures are usually small - a few hundred K. Once per month, the database is refreshed and that can be upwards of 20 megs in size. -steveMicrosoft MVP Windows Live / Windows Live OneCare & Live Mesh Forum Moderator