If you're using wireless, make sure you have it locked so you cant be 'done over' by drive-by wi-fi-jacking. At home I can see someone elses wireless network and it's not secure. I went round with the intention of telling them how to tighten it up but they were out (must go and visit again) - Whenever I visit a relative in london, I can find a wireless network from his flat. Infact, using a PPC, I once found more than 20, entirely open wlans from the top of a London Bus just outside Downing Street. You may have had someone stealing your bandwidth for months without knowing. If you know how/where, look up the routers log and see if there's any MAC address that isnt yours in there.

So - that's #1 - lock your wireless network with a 10 digit code.

#2 - Firewall yourself. WinXP has one which is just about OK, but there are good ones out there available.

#3 - Norton or similar

#4 - Regular runs of Spybot and Adaware

#5 - Use Firefox rather than IE ( I think you already do though )

#6 - Get yourself a Gmail account and setup Outlook / Thunderbird or whatever Email client you have to automatically forward all email sent to you, onto your gmail account. You can do this with 'rules' in Outlook, they're very usefull and powerfull. Thus - if you machine goes totally arse-up, you can still grab emails from the Gmail account! That saved me once just because I accidentally deleted a few emails that had things like account settings, usernames etc etc.

Doug