Thanks for that tip, Falstar - downloaded and about to give it a go

ah - and I don't use Steam. I have an account but they stopped me using it when I changed my e-mail address and now their 'support' refuses to reply to my requests for them to change it so that I can receive the new password they have forced on me. The log-in says my Steam program has been installed into too many different computers, but actually it has been 'repeatedly' (4 or 5 times in 2 years) installed into the same PC, with exactly the same hardware and on the same partition of the same hard drive and from my fixed IP address, when I've reinstalled Windows