How to play .OGG files in iTunes on Windows
Apple restricts iTunes to fewer formats of audio than is deemed good. This may be for marketing reasons, as they want to promote their own format (.AAC). However, the community of iTunes lovers have discovered work-arounds to play OGG files on iTunes.
Note: Installation instruction for XIPH given here is only for Windows. However, XIPH is also available for Mac - see their help files.
To play OGG files, you need to download XiphQT, a small utility. After extracting the contents, copy XiphQT.qtx to the QTComponents folder of QuickTime application folder. Usually, the location of this is C:Program FilesQuickTimeQTComponents
If QTComponents folder doesn’t exist, create it in your QuickTime installation.
As an alternative method, you can also install OggDrop to play OGG files in iTunes.