My computer can be infected with WM /PESAN.A. I can found many files that can be infected with the WM /PESAN.A on my compute. So, I can searched for the WM /PESAN.A on the internet and at that time I can came to know that it can be s a virus. I could not understand why Escan antivirus, that I am using in my computer could not alert me about this virus. I scanned my whole system, but still it displays no infections in my computer. So, I am totally confused with how to remove this virus. I am using Windows XP operating system.