mcafee virus scan

So, I am unable to enable Virus Scan on my laptop. It was enabled, but now it's not, and "click here to enable" isn't doing anything.

The fabulous and brilliant starkeymonster suggests that I need to update my virus definitions, that a virus is disabling the scan. I ran a scan but nothing came up. I tried going to the website to do this, but couldn't find the right spot. Can anyone help? I do use the automatic updates, but apparently this wouldn't be covered by that?