Comodo seems to slow my system down a lot

I just installed Comodo 3.0 on my friend’s computer after your Avast forum freed it of viruses and malware. It seems to slow the system down a lot. On boot up it takes forever to be able to go to the Internet. Before I returned it to him, I would end up getting three copies of IE up because I thought clicking on the quick launch icon wasn’t working. He is running XP Home service pack 2.
Jim ???

How much RAM memory does your friend have?

The Defence module may be increasing the resource usage, as Tech said we really need to know more about his system, including the CPU.