This site is a Fake I tried to use this piece of crap and I got the 'Your PC will be unusable' $#*!. Here's how to remove it. (Tested by me on Windows 8 only)
For Windows 7/8
1. Search for 'Windows Defender'
2. In the 'Home' Tab, click on the big red 'Turn On' button.
3. Wait a few minutes. It should find a virus soon and remove it automatically.
For Windows XP or below
1. IDK how but I would guess running your antivirus would do the trick.(I hope you have one)