My 27″ iMac upon which I work on for all my development work is an amazing computer. I purchased my in spring 2011 and it was just over a year old. Most computers, particularly PCs based on the Windows operating system, need a rebuild from now and again to remove any ‘rubbish’ and clutter that every day use can add to the system. Therefore here is how I set about reinstalling the operative system and starting again.
Step 1 – Back Up
This sounds obvious but the first stage to rebuilding your machine is to backup all of your content and data that you want to keep. I am not really talking here about applications as you will want to install these from fresh, either through the Mac App store or the original downloads or install CD/DVDs provided. What I am talking about is the documents, presentation, images, video and all the other stuff that you will of course want to keep.
Although I use Time Machine to backup my Mac, which is an excellent fail safe, Time Machine backs up the whole system, including that ‘rubbish’ that builds up over time. Therefore it would be pointless to rebuild it using this backup. Therefore the night before I scoured my hard drive on the iMac for all the stuff that I wanted to keep and then copied this to an external hard drive.
Step 2 – Boot Your iMac in Lion Recovery Mode
In order to be able to delete all the files on the hard disc of your Mac you will need to restart your Mac. On restart (when you here the restart noise) hold down Command + R on the keyboard. A window will then pop-up with some options.
As we want to start from fresh I choose to use Disk Utility in order to delete the main hard drive in the Mac. Then I went through the steps of reinstalling Mac OS X, which is another options in the pop-up window.
This takes a while but puts a clean copy of OS X Lion onto your computer. Your computer will then restart and it will act as if it was the first time you turned on the computer.
Step 3 – Setup OS X
OS X now boots and it will take you through the setup process in the same way as when you first purchased the computer. You will have to connect it to your Apple ID, enter a username and password etc. and choose some Keyboard and time settings to use for the system.
Step 4 – Copy Over Your Documents and Applications
Now you can use the external hard drive you copied your files onto in order to copy them back to your Mac with its brand new installation of OS X. The approach I take here with applications is to only install an App, when you actually need it. This will speed up your system and you will be surprised at home many of them you never actually re-install.
So there you have it a quick guide on reinstalling Mac OS X Lion to give yourself and clean factory settings install to freshen and speed up your Mac.