My system is infected with serious virus problem. My friend just gave his usb drive to add some movies. After connecting the usb there was tons of virus detected on the same. I am getting a constant not valid win32 application error on my screen. I was using a free edition of AVG before which looks to not working well. I bought Norton 360 here. But when I try to install I am getting same error on the screen. I contacted the customer support of my pc manufacturer who told me to install KB893803 update. But the installation is giving the same error. What should I do.