Starting up your Mac each day may seem a simple thing, right? Just press the power key on your keyboard or main Mac unit, hear the Mac chime, and then get to work, right?
Sometimes, though, you might want to boot a Windows partition with Boot Camp, or start up from a network volume. Heck, you might even want to start from a completely different OS X disk.
In that case, use the following keyboard shortcuts to do so.
When you start up your Mac, hold the C key down to startup from a CD or DVD, like the Mac OS X Install DVD or flash drive that came with your Mac. I hold the C key down, then press the power button, and keep the C key held down until I see the little spinning gear-like icon. Then you can let go.
If you want to start from a different partition on the same disk, or a different hard drive completely (it still needs to be connected to your Mac, though), simply hold the Option key down when you press the power key to start your Mac up. Again, hold the Option key down until you see the spinning gear icon.
Then, you’ll see all the available startup disk iconsin a horizontal row on your screen. Click the one you want to startup with with your Mouse, or navigate to it with the arrow keys and hit the Return or Enter key..