Too bad you do not use MSN as I can be here all day trying to explain this typing.

I don't even know where to begin.

First of all converting a sound file .OGG into a .AVI video file is pointless.
Converting NSV files to MPEG or AVI is a pain in the azz.

The trick here is to find the player which is right for you. (There is no perfect player for me)
I personally use several players for different files and I never use the same player. Sometimes I get bored and change.

Players I use,

but not in any order are

VLC (Video Lan Player)
Irfan View
Windows Media Player Classic
Crystal Player Pro
WinAmp
The above, I use normally for videos.

For sound files I use a whole group of other programs depending on what I am doing.

I really dont know what else to tell you.

Holla back if you still need me