A *big* thank you to this board, thread, and in particular "BLinAZ". Found you guys via a g*ogle search containing the quoted error in the first post interestingly enough

.
I just today upgraded from an e2140 dual core + 7900GT, to q6600 + 8800GTS/512.. I'm running Vista Ultimate, and TV card is an "old" Dvico Fusion 5 RT Lite.
Well, a few interesting things happened. Ever since upgrading to Vista, I found that Dvico's software didn't work (5 Lite NOT supported properly in Vista, got an "ep 45 authentication" error and so forth - have to use XP drivers and no amount of fiddling would get it working right). Nor was I able to use the most recent drivers - I had to go back a few versions. Needless to say MCE worked just fine, a bit clunkier than I'd like, but nice none the less.
Anyway, upon the switch today, I got the noted error (and another) in this thread, went to upgrade...Still didn't help MCE. But the Dvico software *worked*! Even the most recent release. Still, as silly as it sounds, I have gotten used to MCE, and actually like the MS (.dvr-ms) file wrappers.. I like how it keeps plenty of info on my captures, like the show/episode names, descriptions and so forth - makes it easier keeping track of stuff later on.
I find it a bit odd that the activation mechanism didn't get triggered, but MCE's DRM *did*.. Especially considering all my captures are OTA un-DRM'd stuff - and I've been able to edit (to snip commercials) the files in Video ReDo without issue (other than needing to run Admin more w/ dvr-ms files; didn't need to on TP/TS captures. Guess it just boils down to me not knowing all that much about MS's DRM schemes (as I try to avoid it wherever I can!).
Sorry for the rambling, hopefully if anyone else comes across this and my long winded post helps at all then it's all worth it.
And thanks again! It's nice to have MCE operational again without resorting to format/reinstall or something

(minimal effort is always preferable).
ps Anyone else that runs across this thread with an issue like ours, don't let the ZUNE reference deter you! I've never had any kind of MP3 store program or similar on my system but the KB article did the trick!