Some 9 months again Malware University cleaned up my Pc and made recommendations for the level of antivrus, spamware I should use. I followed them and it has worked v. well. A catalog of stupid errors by Talktalk (of which more in due course) left me without broadband on Feb 10th and I signed up with BT. BT are suggesting I use BT Yahoo! online protection which includes Norton antivirus and other programs which I don't use. If my present set-up has worked well is there any reason to use BT Yahoo! online protection?