Thank you! I didn't see the option there at first, but I didn't look hard enough. Also, I'm trying to recreate an external cd drive just for practice, and I made the solid with most of the details. Is there a way to "cut" the front of the drive off, and make it into a new part? It's hard to explain, but the front of the drive pops out so you can put a cd in, what's the best way to go about making the "door" of the drive. Thanks!
Grundey: I moved this to a new Question to be easier to find in the future.
Since you are using ST4, you have a couple options....
You can model the two in separate part files and combine them in an assembly (you will need to do this eventually)
you can model them together (as you have) and then use the Divide Part command to separate them into two separate part files and then combine them into an assembly. You will need to have surfaces created at the separation interface to do this.
In ST5 and beyond, for the second option, you can use the Multi-Body Modeling methods posted by others, but that is currently not an option for you since you are on ST4.