Mmm . . . thanks for the input, but I'd better stop here. I'm being drawn in to a challenge again. I used to enjoy them, but as I get older I'm starting to lose more and more of these battles.
I now have a usable Dual Boot unit and when I tried the compatibility in W7, it seemed to be working, and indeed announced the file was the Launcher something. When I caused it to run it went to Setup in C drive. Potentially disastrous as my English MS word is running in there under Vista.
Sony warned they do not support dual boot. Maybe this is strong evidence of the fact, cos I was running in D drive's W7 OS and I don't understand why it would reach out to another OS.
Thanks again, but quitting while I'm ahead.