I was using release edition of windows vista ultimate since last two months (MSDN Subscription) and I never had any issue with it whatsoever. I was contended and quite satisfied until i came across this issue.
The issue: Windows media player and built in application on vista could not be repaired – it seems Microsoft is really confused. See screenshots below.
Yesterday while watching an online news I was asked to download an activex control. Since this was coming from a reputed news channel I presumed it was okay to download the same. Well, well, well once I downloaded the same, I was not able to play any video online – be it a webcast, online streaming audio - basically anything which uses windows media player activeX control.
Well i can' say it for sure that it might be the problem with the activex but what ever the reason it be, i for one has corrupted my windows media player for some reason.
I glanced through the logs and this is what the log says:

It seems Microsoft's suggestion is not correct. They should know that there is no known way to reinstall windows media player in Vista.
To me it seems the only way to fix such errors is to restore to the previous safe point which i don't have any. There is no known way to fix a corrupted windows media player except to reinstall (we all know this and this is the recommended way to fix corrupted windows components - even the error log says so), but the same won’t be applicable in my case.
Until a workaround is found I will not revert back to Vista again.