Such topics are covered hourly it seems at http://forums.cnet.com/spyware-viruses-security-forum/?tag=rb_mtx;f06-fd
I have a Sony Vaio,model PDG-7R2L, T5600 @ 1.83GHz, 1G Ram, Microsoft Windows XP Media Center Edition Version 2002 SP 3
My computer is running extremely slow. It is booting up in selective startup and when I change it to normal startup it gives me an access denied error. Internet explorer opens and hangs without going to the opening page. I try to close it and it does nothing. I click on windows update and get the message "Windows cannot find'(null)'. Some exe programs give me application errors. I ran Hijack this and it didn't show any running processes.

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