How do I remove antivirus 2010 for XP?

I've gone to tutorial website to delete this rogue virus. They all lead me to a program called malware bytes. I've also tried stopzilla. Here's the problem. Once I have downloaded the program, the antivirus 2010 virus pops up before I can install it. I NEED to figure out how to get rid of this. I know how to go into task manager and get rid of av.exe. But it just keeps reappearing and popping up. Thanks for your help.