Go into the security center in control panel and turn on the XP firewall.
Once you're behind it disable the Windows Messenger Service.
Instructions here : http://support.microsoft.com/kb/330904/en-us
Now go download and install all the XP updates from Microsoft : http://support.microsoft.com/wupd
Now get the following free
programs : AVG http://www.grisoft.com/doc/289/lng/us/tpl/tpl01
ZoneAlarm : http://www.zonelabs.com/store/conten..._freedownloads
Spywareblaster : http://www.javacoolsoftware.com/spywareblaster.html
Spybot Search & Destroy : http://www.spybot.info/en/index.html
Adaware : http://www.lavasoft.de/software/adaware/
Defender (Windows beta software,which means it's still being tested. You don't need it but you may want to try it): http://www.microsoft.com/athome/secu...s/default.mspx
Now disconnect the computer from the web. Depending on what sort of connection you have you may actually have to shutdown the computer and physically disconnect before you boot again.
Go into the security center and set it to "I will monitor my own security" and disable the XP firewall.
Install ZoneAlarm and use the defaults ( Use some sense here please, you can always tweak later and yes IE needs net access).
If you have to shut down to reconnect to the net do so, if not reconnect and begins installilng the other software, they will need to be updated. An anti-spyware or anti-virus program is only as good as it's most recent update.
Zonealarm will sk you about each one, say yes.
Reboot as necessary, run scans for the first time.
You're done (unless you've been tagged by something.).
Forget you ever heard of McAfee