Windows XP Security
"Without your knowledge or explicit permission, the Windows networking technology which connects your computer to the Internet may be offering some or all of your computer's data to the entire world at this very moment!"
The above is a quote from Steve Gibson, of Gibson Research Corporation which is located at: https://grc.com/x/ne.dll?bh0bkyd2
I found the Gibson Research site to be quite amazing.
The first time I went there it told me the name of my computer, work group, and how many ports were wide open to intrusion by potential hackers and vandals.
After a few minutes at the Gibson Research, with the help of Steve Gibson's expert
recommendations, I changed simple settings on my machine, making it secure enough that
intrusion was no longer possible.
If you have any concerns about security when you're online I highly recommend that you
visit Gibson Research Corporation and run the two tests called
Shields Up! and Probe My Ports.