I have two 320 gb HDD's in my laptop. I built a new desktop this summer, and no longer need the extra storage in the laptop. Is there any problem with putting the laptop HDD (the one without the OS) into my desktop? I realize that I will probably need some sort of 3.5" to 2.5" adapter, but I think my computer case came with one.
Another thing to consider is you need to make sure that your Laptop Hard drive has an interface that your new Motherboard can accept. Just in case you have an IDE drive or even a SAS drive.