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Do yourself a favor and post the specs of your machine before these guys tear you a new one hahah
 
what's type of the video files can handle with this ibook? And what's resolution?

What's your OS and RAM? You can find it out on About This Mac under the Apple logo. If you didn't know this already, the type of video files it can handle all depends on the video player. If what you already have doesn't work with some files, then Google that video format and look for a video player for your OS. And if you have a high enough OS for the video, your specs won't matter for whether you can play certain types of video or not, though higher specs will allow you to play it well.
 
Watching videos on a computer with an 800Mhz G3 processor is like going on Youtube in Windows 3.1. It won't work very well.

I would also recommend doing yourself a favor and looking for a better laptop (a powerbook G4 at least; those things are getting old enough to find in computer garbage). Ibooks are horrible. I repaired those things at work for over 5 years. Nothing but problems! They're poorly designed and poorly built.
 
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