How can I view the contents of my computer on my Apple TV?

how do I watch my computor on Apple TV ?

turn on home sharing on your computer and apple tv.

once it's on, then anything in your itunes library on your computer (movies, music etc) will be accessible on your apple tv. the apple tv accesses it via itunes so itunes on the computer needs to remain open.

Although titled "Home Sharing", I think he's actually referring to the AirPlay Mirroring function...this function is only available on certain macs and only using the later versions of OSX, so if you can't get it to work, you'll need to google the requirements (as they are readily available online in about a thousand different places).