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.
Also if you want to start from a different partition but on the same disk, you can 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.
After doing this step, you will be able to see all the available startup disks, simply use the arrows keys to enter any partition you want…
Haven’t ever used Mission Control on your Mac ? Well you are missing a lot of great features, because Mission Control allows you to separate out of your apps, full screen and not, to be just that much more productive on your Mac.
Once you activate Mission Control (the default is the F3 key), you can then use the Control-Arrow keys, Left and Right, to navigate between Desktop spaces.
If that’s not enough fine-grained control, you can also use the Control-1, Control-2, -3, -4, etc. keys to navigate directly to the Desktop space, in any order.
There’s a default of four Desktops in Mission Control. If you want to delete one, hit the Option key to see the iOS-style X button in the upper left of the Desktop at the top. If you want to add one, click on the big Plus button to the far right once you hit the Option key.
Removing any app you want from sidebar has been a very easy way, just drag any app you want and poof! that’s it you are done.. Today, however (and for quite some time, really) you can’t just click and drag the sidebar items away without giving it a little more thought. That’s where this handy keyboard shortcut comes in.
When you want to remove items from the Sidebar, including things like AirDrop, Desktop, All My Files, Downloads, Applications, Documents, and the like, you’ll need to hold down the Command key and then click and drag it away.
Right? So simple it hurts. But there’s probably a reason the software geniuses at Apple changed this behavior.
My guess is that too many people were randomly clicking on Sidebar items and then losing them, and then having no clue how to get them back over there.
If you don’t, then here’s the trick for putting items into the Sidebar. Find the folder you want there, Documents or Downloads or whatever, and drag it to a spot in the Sidebar. If you drag it between items already there, you’ll see a blue line show up where it will end up. If you drag it to the bottom, it will go at the bottom of the list. Slick, right?
To avoid the endless loop, there’s only one keyboard command you need to know: Command-Tilde. The Tilde is the funny little ˜ sign just above the Tab key on most Apple-compatible keyboards.
You won’t be able to jump right into a leftward looping Task Switcher rut right away, however. You’ll still have to activate the Task Switcher with a Command-Tab and then, still holding the Command key down, move your other finger to the Tilde key. Boom! You’re now moving through the open apps in the reverse direction.
