All is not as it first appears in the computer world. Several users have been caught by this malware at our school recently. It is not really a virus, it is a very obnoxious program that tricks people into saying that they want to install it. The quick and dirty solution is when you first see activity like this, simply close your browser (Internet Explorer, Firefox, Safari, etc.) Note that this is a Windows thing, although similar things can happen in the Macintosh world.
If you Quit your browser at this point, you are done with the problem. Relaunch the browser and go about your business (although maybe not by going back to this site.)
It says that 'Virus Protection System is starting now', scroll bars go by, and you are left with this screen: (shown in the next step)
A few things to note: this screen shot was taken on a Macintosh running OS 10. This picture is within a web site, but designed to look like a Windows desktop, complete with flashing 'Virus found' warnings, etc. This is totally bogus! If you quit your browser at this point, you are still safe. If you click 'Repair All', see the next screen:
Again, this is taken on a Mac. But note the 'AntivirusInstaller.exe'. Anything ending in .exe are 'executables' in the Windows world. They are programs that run and do things. (This window would look different in Windows - it would give you a chance to 'Run' the program.) THAT IS THE FIRST REAL, DANGEROUS STEP. IT INSTALLS THE PROGRAM! If you did, you would have a very obnoxious program in your face at all times on your computer and you would need to remove it or call your tech person...
If at school, call your tech person. At home, Download MalwareBytes from malwarebytes.org and install it and run it. It will clean this up.
When I clean this at school, I run MalwareBytes, I then go to the Documents and Settings folder and remove the user's folder (first saving their Favorites). But don't delete this at home - that folder contains all the documents! But there might be some caches and other files in it that are worth deleting - I don't really know.