I checked out that site on my work computer since it's gov't owned and has nothing on it they don't already know about. And I am able to nuke and re-image it if things go wahooni-shaped. At that site, they'll do the check for you, but you can do it manually if you want to know and don't want anyone else scanning your machine. I got the details on what it's looking for from
here.
They're looking to see what DNS your machine is being routed through to get internet access. Your ISP will give this to you if you have a static connection and it's automatically configured if you use a dynamic connection.
In case anyone is curious and doesn't want to use the link...
Open up the command (CMD) window
Type ipconfig /all
You should see settings similar to this:
Look at the settings for DNS Servers. If the IP addresses there fall within any of these ranges, you have a problem.
77.67.83.1 to 77.67.83.254
85.255.112.1 to 85.255.127.254
67.210.0.1 to 67.210.15.254
93.188.160.1 to 93.188.167.254
213.109.64.1 to 213.109.79.254
64.28.176.1 to 64.28.191.254
If you have a problem and a dynamic connection, you can reboot your machine to reset it or try this to fix it:
Open a command (CMD) window
Type ipconfig /release
Type ipconfig /renew
If you have a problem and a static connection, you'll need to get the DNS information from your ISP and re-enter them in your Local Area Connection settings, just as you likely had to do when you first got set up.
If you do all this and your machine reverts back to the blacklist IPs above for its DNS settings, you still have the buggy bug on your machine/in your removable media somewhere or you keep going to a site that's putting it on your machine. You might also want to check your router and make sure it's not configured to route through the blacklisted IPs.