Thanks - that was the nudge to making it work. I did have the correct Quicktime key, but didn't prefix my name with a 'salutation', probably one of the dropdowns in a mandatory field used at registration. Hey presto, my nine year old box of tricks, "obsolete" according to the boys & girls at the Leeds Apple shop, adds one thing more to its pre-crash repertoire.
Unfortunately, the trick I was hoping my originally paid-for application would perform, that is converting .wmv to .mp4 video format for Quicktime playback, remains as intractable as before without using a tool external to Quicktime. QT 7 pro *can* run media files not in one of its recognised formats, but the original file has to be exported from source (.wmv) to alternative (mpeg-4) forms first - and QT 7.6.4, pro or otherwise, doesn't recognise .wmv as a importable "movie" format in the first place! Doh !
I've already been doing the conversion process in up to half-gigabyte sized batches (they run overnight) with an excellent, and properly backwards compatible, video converter application called Prism (from NCH), but it's not shareware and the trial version expires in "a few days". Continuing to use Prism is not going to be a huge cost, but it would be preferable if Quicktime DID what it *still* says on the tin, that is (from http://www.apple.com/uk/quicktime/extending/):
"QuickTime 7 Pro can convert your media to different formats, so you can watch a movie or video on your iPhone, iPod and Apple TV."
Not .wmv movies it doesn't !
Iain.