I have Smart Security & was going round & round trying to uninstall & reinstall. I'm not a big fan of User Forums, but finally found ryuuki86 who had a similar difficulty with the AntiVirus program. He found the C:\Program Files & deleted ESET, that coupled with using my original Username & Password, as opposed to the ones supplied to me specifically for this problem, let me Reinstall. He said: Default Re: Insufficient Privileges Fixed it using a bit of brute force and ignorance. I had tried looking through registry entries and such but soon got bored so I resorted to the very reliable way of digitally applying a sledge hammer to the problem. For anyone else experiencing this issue, here is how I resolved it: Boot in to Safe Mode (continually press ESC while booting, may differ from system to system, my other PC uses Backspace, while my Laptop uses F10) For Vista you may have to select F8 from the screen displaying Windows Vista as an option - then select Boot in Safe Mode. Once in Safe Mode head to C:\Program Files\ and delete the ESET folder. Then go to C:\ProgramData (you may have to type this in the explorer address bar as it's normally hidden) then delete the ESET folder in there. Reboot into Windows, then run the installer - should be working again now! ******************** Tried to find him in the Members, but he's gone. I sure do thank him.