If you’ve had your Macintosh for a while, you’ve undoubtedly run into the occasional video on the Web that you can’t view. They’re usually classic Windows formatted videos like Audio Video Interleave (AVI) or Windows Media Video (WMV). This can be easily remedied and it doesn’t even involve running anything other than QuickTime to watch the videos.

QuickTime is an advanced multimedia authoring and playback system. As such, it has support for a wide range of components that expand the functionality of QuickTime to support a variety of technologies – including AVI & WMV.

There are two things you need to download. The first is Perian. This is what will give you the ability to play back AVI files (and DIVX, FLV, MKV, GVI, VP6, VFW files as well). Perian is open source software, so there is no fee for using it. However, the development team would appreciate a donation if you get a lot of use out of their work.

To be able to view WMV movies, you need to download the Windows Media Components by Flip4Mac. There is a free version of this that will allow you to play back Windows Media in QuickTime as well your web browser. And you can also upgrade to one of their other versions that start at $29 and give  you extra functionality like being able to convert Windows Media to another format such as MPEG-4 AVC.

Once you have these two QuickTime components installed, you’re prepared to play virtually any video you might come across. And you never need to think about it. Just open them in QuickTime as you would any other movie.