The most common thing here is that some part of Windows attempts to automaticly connect to the Internet and check for updates. This also applies to various non MS software as well.
For starters go into the Control Panel and turn off Auto Updates in the Security Center that will prevent Windows attempting to log onto the Internet and check for updates automaticly.
The next thing you can do is to go into the Control Panel again and turn off the ability of the modem to Auto Dial as I don't have a version of Home Loaded here I can't tell you exactly where this is in Home as the Pro version is a little different. That should stop most of the call outs but you may need to go into every program that attempts to Auto Update and disable this option in them as well.
Of course the easy answer is to remove the internal modem fit an external modem and switch it off when not needed it will allow better security as well as the computer will not be connected to an active telephone line while it is on and this one appears to be on constantly.
Col
