HELP! Antispywaredeluxe infected!

If anyone could help me, it would be great.

I use firefox as my primary browser. I use a home edition windows xp computer.
One day while surfing stupid antispywaredeluxe (asd) opens up and starts scanning, etc... you know the drill.
Well, now every day it does this... closes my browser and pops up with its stupid little annoying &*#%@* fecking interfering pop up.

I cant find any of the files that some sites say to look for. I cant seem to get rid of this fecking thing. I even went to the site itself and wrote a nice long nasty letter to them telling them that their scam was not, under any circumstances, would cause me to download and pay for their piece of shit program... etc etc.
Not that it will do me any good, but I dont know how to get rid of this thing. Everywhere I have looked... "download our program to scan for the 'bad' program, and pay us to rid your computer of it"
I am just so sick of this bloody thing. Frustrated and tired of trying to find a way to get rid of it.

So can anyone help me? Please????