I would second the Symantec thing. I have no idea how they stay in business. Can't say enough good things about Trend Micro, but I am referring to the corporate edition. AVG and NOD32 make good products as well.
While XP Pro is the way to go, don't be too hard on yourself for using Vista. I use it at home simply because some day it will probably be forced on us. It isn't that bad.
I think Microsoft should take a cue from McIntosh, and come out with smaller updates more frequently. Part of the difficulty with Vista is it is such a complete feature shock. Also, Bill tends to think we are all stupid when it comes to security and attachments and more and more wants to hold our hand when it comes to these issues.
The other thing with Vista that not everyone is aware of is that it absolutely requires 2 GBs or RAM and, if you are going to use, Aero, you need a very good Video card. There is also a way to strip it down so it uses less resources.
