How in the world do I set it up so I can use my computer speakers as the monitor? Or for playback?

I can't find the option anywhere!

If you are using a USB interface of some kind then you will have to hook a monitor or headphones up to it to hear the playback.

It's a firewire device, so you mean that there is no way to have playback through the computer speakers? I don't think that's true, the recording is made with the computer, with the software.......

In the windows control panel, go to the sound options. In the audio tab, change all your default devices to the firewire interface. Then you will probably need a 1/4" to miniplug adapter to hook your computer speakers into the output of your firewire interface. Make sure you have the right ASIO driver selected in the Device Options in Cubase too.

What hunta said will probably get you going. However, you never said what kind of interface you have.

If you have any kind of audio interface hooked up then you cannot play back through the PC internal speakers - it will have to come back out throught the interface.

I doubt he wants to use his internal speakers.. He probably has regular external computer speakers, and you can certainly hook those up to an interface.