For those who've already responded please note the following.
1) as far as I can tell, Gilles has a perfectly valid copy of Windows 7.
2) He has had some major corruption problems - some of which were addressed and corrected in his original thread in the MS WGA forums that he pointed to
3) (Karl - please don't pre-judge!)
4) The poor guy has been fighting this for a month now - with what little assistance I have been able to offer - and eventually I directed him to a repair install. This came up with a very general erorr message, which is why I drected him to these forums (they are more likely, I suspect, to produce a viable solution than the normal MS Answers forums)
Give the guy a break, please, and try answering the questions, rather than pandering to your prejudices.
(as far as the CBS.log file is concerned the only person I know who can reliably read them is Niemiro - who has been on the sick-list for a few months now)