What is the best way to install a new hard drive on my MacBook running OS X?

by on September 17, 2012

Q: The harddrive on my macbook circa mid 2010 laptop is old and only 250 gigs.
I just bought a 750 gig hard drive to replace it.
I want my 750 gig hard drive to have a fresh installation of mac osx mountain lion. I don’t want to migrate everything over from my old hard drive. I bought a hard drive enclosure, and my intention was to install the osx on the new hard drive while its plugged into the usb port, then I would swap them out, and manually move apps and files over.
What’s the best way to do this.
Should I install the hard drive first then install the os? Should I install the OS while its in the enclosure as an external drive? What should I do and what are the steps to do this. Also any links you recommend on how to swap out the drives would really help as well.

One Response to “What is the best way to install a new hard drive on my MacBook running OS X?”
    Picked as best answer

    First you’ll need to make a bootable install disk/usb for Mountain Lion. Follow the first part of these instructions to create the install disk/usb:


    Next, use your favorite backup utility and do a full system backup of your drive just to be safe. If you don’t have anything to do this, consider CrashPlan or Time Machine.

    Next swap out the drives. Here is a great guide for swapping out the hard drive.


    Make sure to read it fully before starting to make sure you understand all the steps and have all the needed tools.

    With the new drive installed follow the 2nd part of the Clean Install OS X Mountain Lion Instructions to get Mtn Lion fully installed on your new hard drive.

    After that hook up your old drive via the external enclosure you purchased, and move over files as needed.

    Make sure to have other backups of your data so that if you screw up you don’t lose your stuff!