it doesn't look like you've got any obvious malware, from your task list.
if you don't want to reinstall, go into the add new software control panel and uninstall anything you don't use. retail computers come loaded with all sorts of crappy software, like AOL. some things you have to keep, like IE, regardless of whether you use it or not.
also, do a windows update.
download and run some anti ad/mal/spy ware software. i use AdAware (
http://www.lavasoftusa.com), and spy bot search and destroy (
http://www.safer-networking.org/en/download/). but once you clean out your system, don't leave those programs running. set their options to not autoload. do this with all of that software that autoloads helpers and shit, like realplayer (if you don't use realplayer, get rid of it. it's evil). there's no easy way to disable ituneshelper and ipodsvc, though.
also, defrag your hard drive(s) and make sure all your drivers are up to date.