fighter against computer virus

so my windows laptop was infected again. I didn't go to any bizzare website, actually I rarely surf on that machine, as it is in my office and sit on the other table. I use it to plot data only. The virus puts a big red button in the windows tray and a floating dialog saying "The computer has virus". I guess it needs some attention. My anti-malware software, "superantispyware" doesn't work now. The virus is so vicious that it blocks anti-virus software to start, and this virus is starting with Windows, before anti-virus software starts.

Then I came across a software, avast (www.avast.com), which scans virus at windows boot screen, a.k.a. the big blue screen. Ha, it catches virus at their nap time. Wow, this is like good vs. evil, good always wins. I guess when virus goes one step further, like infects computers at boot time, there will be software scans at BIOS time; if there is virus infects at BIOS time, there must be virus scanner detects at machine power-off, say, a laser beam shoots at your hard drive, maybe?

Avast has a free version, of course.