http://www.computerworld.com/action/article.do?command=printArticleBasic&taxonomyName=Security&articleId=9134928&taxonomyId=17

CSO –
A common misconception is that a shiny new computer is more or less secure because it hasn’t yet been exposed to the Internet’s sinister underbelly. But the truth is, these machines come out of the box needing scores of patches, some basic security software downloads and the disabling or replacing of items security pros don’t typically trust.

Step 1: Uninstall Stuff You Don’t Need
Step 2: Install Firefox
Step 3: Install NoScript and other Firefox add-ons
Step 4: Search for all needed Windows patches
Step 5: Customize your AV/firewall package