Ok....its has nothing to do with Nortons.
Here is 2 options.
Option 1.
Here is how you fix the problem Stuart.....I hope your experienced with computers as its no easy task....
http://support.microsoft.com/default...b;en-us;324767
Option 2 if your very very lucky.
Go to C: drive and open up your windows folder...then go into your repair folder and find the file called autoexec.nt copy this file into your system32 folder.....
If your lucky this will work..if your not you have to do option 1....if option 1 is too difficult then I'm afraid a system format is your only option...or send it to a tech.
Hope the easy option 2 works for you.
P.S I never got that Imageplus program to work in the first place.