Windows Protection Suite Virus infection

recently i've started getting a message that says "Warning Your Computer is Infected" this warning directs me to a site called Windows Protection Suite which offers 3 types of payment to fix the problem (6month, 1 year and lifetime). An icon for this site keeps coming up on my desktop. I've got a HP with windows XP and I'm using Firefox. I using ZoneAlarm, AVG virus protection, Malware, Adware and CCleaner. But since the warning has been coming up I cannot run AVG or Adware. Is this some kind of Spyware and how can I get rid of it?

Take a read through this and then start a fresh thread in this forum and post accordingly. Please don't forget to include a brief description of your problem, and somebody will be along as soon as.
Helpers look for posts with zero replies which is why you need to start afresh and why i'll lock this one.