From time to time when trying to play certain video files and always when opening WinAVI Video Converter it says that Windows Media Codec 9 is not installed properly. I use Windows Media Player 10 use WinXP and have installed ffdShow, AC3 filter and Klite full codec pack as well as many video converters/programs. Would any of these have caused the problem? I have the tools, NeroInfo Tool and Gspot. Is there anything on my PC that I would need to be rid of here? Any help would be greatly appreciated. I've been told that codec debugging is a pain.