I'm not a fan of piling on tools. ONE of each type, don't use IE9 or any of its predecessors - Chrome, FF, maybe Safari. No 3rd party cookies, no toolbars unless you are 100% DEAD CERTAIN that it cannot be compromised.
I use/reco AVAST free edition for xpp and 7, not vista. MSE is apparently pretty good though I would love to see full detail of real, rigorous testing on it
see this, its recent:
Best Free Antivirus Software
I don't see the point in re-installing unless you have reason to believe you have OS file damage - it can/does happen with rootkit infections but usually not with Trojan-class.
If you do reinstall, be sure to scan the media from which you wish to do the reinstall.
you can turn off Defender.
It usually does not get mentioned in these 'security' discussions, but I'll throw one "ringer" into the mix here and explain.
"WinPatrol"
Download WinPatrol 24.0.2012.1 - FileHippo.com
It has a unique sort of role to play. For tech-novices or simply for those who do not want to visit nerd forums to learn of the latest steps to keep tidy etc etc, winpatrol, once the initial setup is done [that takes a little work, just like Autoruns does] sits unobtrusively in the background and monitors for any new executable that happens along and tries to fire itself up. My instruction to the user is simple: "if you are not 100% sure what it is that is newly trying to insinuate itself in your stack, say 'no' ".
In real use, people click all sorts of phony links, load up IE with toolbars, gimmicks, games, "coupon deal of the day" - endless dangerous things. WP can greatly reduce the risk and clutter if the user will just let it do its job.

Quote: Originally Posted by
squidgy
Sorry for the delay. Thanks for the recommendation. I will check it out.
Any other opinions as to whether I should reformat or not?