I downloaded Realplayer SP Gold to see what if it was good. After I uninstalled it, I tried to play my rmvb files with KMplayer, I couldn't play them anymore! I tried to use Real Alternative's Media Player Classic, but it didn't work. I uninstalled KM and Real Alternative but still doesn't work. KM goes error code 80040218 I searched it on the KM forums but I still don't get it. I can't play my 100GB+ worth of rmvb files now. Edit: I guess it screwed up Real Alternative, Not KM, because KM uses Real Alternative's Codecs.
So what's the lesson you learned today? Don't use obscure file formats that only one to a few media players can play. Oh, and I usually think of K-lite for the codecs, but Combined Community Codec Pack (CCCP) is a better version of that. I like using VLC to play VIDEO_TS files as well.