Windows XP has a new “bad” habit : to “call home” = connect via Internet back to the
Microsoft servers without asking for your permission !
It starts already at the end of the installation of the operating system, where it tries to connect
via the Internet to Microsoft “to obtain latest updates”.
 | Example : Double-click in your taskbar on the clock :  to display the properties of “Date and Time“, select the tab : “Internet Time” : By default, Microsoft configures your XP-system to “automatically synchronize with an Internet time server“, using a Microsoft time server. To avoid such uncontrolled Internet connections, disable this synchronization. |
Windows will also connect sometimes back to Microsoft to check “for Windows Updates”.
Unluckily, the build-in XP Firewall only allows to control incoming “calls“, it doe not allow
to control programs running on your system making an outgoing “calls” onto the Internet.
To control outgoing “calls“, you need to disable the XP Firewall and install another Firewall,
like for example ZoneAlarm.
