Thank you for that. I have just tried the speed test again without Trend Anti virus being installed, and it proved that was causing the problem. At the moment I have 3 weeks to go on that virus software before I need to renew it. So will put up with the problem at the moment until they fix the software, or I find another one - that works, and is cheaper!
Reference Apple computers being free from virus attack, this I think was due to the fact that in the past very few people used Apple computers. Therefore hackers left them alone. But not now!