Security Self-Help

Performs a set of basic security checks appropriate to Windows Vista and Windows XP computers (not servers).

It can also repair many of the problems it may find, such as weak user account passwords. If the tool discovers any significant security vulnerabilities on your computer, it will alert you to this fact, and tell you how to address the problem, in many cases offering to do the repair itself. For help you can use the tool's Help facility, which will take you to the appropriate web page.