This sounds crazy - -but. Have you downloaded the IE6 update Q818529 from the MS site?This is supposed to be a security patch
I did this and found I couldn`t download a nero update. I have removed this patch and now everything is fine. You can see this patch if you go as if to add/remove a programme from settings.
I have not replaced this patch and things are much happier now with my PC. You can always give it a try and if it doesn`t work download the patch again or can you?