How to restart all the configuration of Ubuntu

[SpecialNeeds]

I need to restart all the configuration of my ubuntu, that's because I ruine something in the configuration of Audio/Video, that's nobody can help me:

http://ubuntuforums.org/showthread.php?t=1587035

Then seems that I need to restart all the configuration, but I don't want to reinstall Ubuntu, because that I don't have a ISO of Lucid Lynx, only the ISO of Karmic Koala.

Thanks for all answers.

[andrewthomas]

If you are just having a problem with mencoder you could just


sudo aptitude purge mencoder
then


sudo aptitude update && sudo aptitude install mencoder