7.) It is critical that you use a firewall to protect your computer from hackers. We don't recommend the XP firewall that comes built in to Windows. It doesn't block everything that may try to get in, and the entire firewall is written to the registry. As various kinds of malware hack the Registry in order to disable the Windows firewall, if using XP it's far preferable to install one of the excellent third party solutions.
If you do choose to install a third party software Firewall remember to disable the native XP one at that time.