A few months ago I got a message from Norton Anti-Virus saying that it detected a trojan horse virus in my computer. Unfortunately it could neither repair or quarantine the file. I immediately deleted the specified file (not really expecting that to solve anything). Ever since then my Dell Inspiron 8200 laptop has intermittently choked on any software graphical applications (games and simple desktop window manipulations), suffering a severe drop in frame rate. Since the virus I have formatted my hard drive several times, starting from absolute scratch, but the problem persisted. I am at a complete loss as to what else to do and would rather like to get this reasonably expensive laptop performing normally again.
Thanks in advance