OK, spoke to Toshiba technical support and they told me to download the McAfee Removal Tool from the Internet which I did. It is a small programme, free to download and quick to use. It cleared all traces of McAfee from my laptop and I was able to proceed with the setup of Kaspersky. However, my Kaspersky was good for Vista so I had to find a free upgrade to the latest version which supports Windows 7 to be able to use it which was a bit of a headache but all is well that ends well. If anyone else comes across this problem, I hope my experience will help them out
