umm, uninstall the codec pack perhaps? (If you haven't already) i assume Oblivion is up to the current patch? Got the LATEST Vista codec pack?
http://www.softpedia.com/get/Multime...-Package.shtml
mansrm81 is right, you can't remove MP11. For some reason, I thought you could. Sorry.
From what you've described, if media Player is working, then it shouldn't need to be repaired. It's not broken. It's Oblivion that has the issue
