A client(Michelle, Cathy's friend)'s HP laptop. Yesterday.
At windows startup, error message kept popping up or else whole system froze, saying windows explorer encountered error, module in question: CLDemuxer.ax
Decided to delete such file from safemode, failed, same problem.
Used Vista DVD to enter recovery mode during bootup. Ran command prompt, thanks to this site, located file in two folders:
Directory of C:\Program Files\Hp\QuickPlay\Kernel\DMP
Directory of C:\Program Files\Hp\QuickPlay\Kernel\Movie
(Apparently, HP issue) Some sites say it's from other programs like Nero, I found no such evidence here.
In the recovery mode, renaming was easy. Problem solved.