Uninstall/re-install PCTAV from
http://www.pctools.com/free-antivirus/. When you have uninstalled PCTAV go to c:\Program Files\PC Tools AntiVirus and delete this folder before re-installing. Try Smart Updating again.
By OS = Operating System, ie, Windows XP, Vista, 98 etc...
To check what is running, you can go to the system tray at the bottom right hand corner of the screen Or task manager.
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