Thanks flyby... Excuse late response. Too much gardening before the Wx changes.
I'm not normally bothered by normal downloads such as e-mails, attachments and ftp transfers. That is, after all why we have our Anti Virus stuff running. But upgrading on-line is different so your advice may be worth heeding. Incidentally, McAfee gave me grief and extra work because I couldn't enable e-mail scanning. Until I found the bit hidden on their Web Site that says you can't activate e-mail scanning on a domestic system. It's all done by Download Scanning.
Incidentally again, I haven't yet figured out how to uninstall McAfee other than manually deleting the files and cleaning out the Registry (which I'm quite used to doing but it is tedious).