The IE 8 install, Checking your computer for malicious software

One of the steps during the Internet Explorer 8 install is, Checking you computer for malicious software:

If you have malicious software on your machine, isn’t it a little to late to be checking at this point?  Is this really necessary? Isn’t this the goal of virus and malware scanners? Maybe malicious software is a code phrase for other browsers, or more likely IE 6