Thanks for all the suggestions on this.
1.I'm running Windows Vista.
2.I've done a full scan using malwarebytes-zero reported.
3.I carried out a full norton removal at the time of installing Avast.
4.Windows Security Center reports- firewall switched off -before loading IE or Firefox.i re-instate it & then same again on next re-start. wasn't sure what Humpty meant on Services set to automatic?
5.Event Manager Audit does not report errors 5025,5029 or 5030-the ones that Microsoft highlights in its Tech Center docs.
I've not used hijackthis log before.Are there any risks? Also how do I locate the log for it to analyse?
If I conduct a registry clean on CCCleaner-which checkbox should I concentrate on?