Answers:
protect your self near a firewall to prevent intrusions in your workstation,use window standard firewall or if you want some item more effectual and professional use ZoneAlarm,it's free.
Better than the above answer:
SWitch to Linux and turn past its sell-by date services
stir to a bsd distribution, encrypt your drive, ipfilters, turn rotten adjectives services except connecting, never run as root, minimalise the browser's memory use, boundary user permissions, etc
Change adjectives non-attendance usernames/passwords such as root other use a pet name and an unusual password something firm to guess.
Keep you firewall running at all times, you could download and use Watchdog (I use it) which will monitor your firewall for you.
http://www.majorgeeks.com/watchdog_d4358...
Do not jump down for social engineering scam. Be completely diligent which e-mails you depart and NO attachments unless you know the character and you know to expect one.