Being realistic I want to be able to do most things: install apps, go online, etc. but want to be safe and prevent any unnecessary problems (i.e. reinstalls!)
From what I've gathered Microsoft Security Essentials would be a good bet? Also, would you recommend UAC is left as is or to be tweaked to be an optimal gatekeeper? Anything else I need to consider? (In XP, I currently have an anti-virus app - mainly for emails.) Are there any gotchas that Microsoft have left in?