OS X: Change Boot Device or Disk
Contributed by David Kirk 
Tagged: Apple Mac In testing of leopard or in restoring a system, the ability to change the boot disk or device is essential. Here are the steps required to change the startup disk in OS X.
As a beta tester, I need to be able to switch from one install of OS X to another. By changing the boot disk, I can boot from my iPod, an external hard drive, or another partition very easily.
1. Click System Preferences
2. Click Startup Disk
3. Select the disk or device you want to use
4. Press the Restart Button
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paul said on January 27, 2009
Too simple…what if the device you wish to boot from is not in the lst?
Anonymous said on March 29, 2010
Under Step 3. above is a snapshot showing a choice of 4 startup locations. I NEVER see more than the Mac OSX10.5 and the Network Startup, NOT EVEN when I have other startup locations with other OSes. My MacBook is a BIG disappointment, in this and MANY OTHER ways, including faulty. But an answer to this question would be great—it may not be the machine’s fault.
EIre said on November 9, 2011
Any idea how can Network Startup be removed from the startup options?