The best thing you can do is set it up for him, if you know how.
1. Check in the security center that the firewall is activated.
2. Download and install Windows Defender from Microsoft. It's not perfect, but it's free and works well.
3. Install any antivirusprogram. That's totally independent of the OS. Free ones that are used by many members here are AVG Free or Avast. Good paid ones are Norman, Panda, Kaspersky, Trend Micro or NOD32. You might want to read through http://forums.cnet.com/5208-7810_102-0.html?forumID=77&threadID=235055
Check that it's set for automatic updates.
4. Check that anti-phishing is enabled in your browser. He might like to set up some anti-popup also. Note that Firefox 2.0 is considered somewhat safer and somewhat more user-friendly than IE7.
5. If you use Outlook Express for email set it to 'no preview'.
The other important thing is how to behave:
a. Only download programs from reputable sources.
b. Don't download from suspect sites (like in Russia or porn).
c. Never, never, never open an attachment from any mail from an unknown sender.
d. Never, never, never type your creditcard number in any page when you don't see the lock in the status bar.
e. Never open spam.
With protection set up, and living by this rules, you are rather safe.
My son recently purchases a windows xp system. He's never owned a computer before. He's quite excited.
However, he's already gotten it infected with virus, so I'd like to send him some web sites to read concerning the proper way to set up and run his system so that he is safer.
What articles or sites would you recommend for a windows xp newbie?