2009 Mackbook Pro Running Slow; Downgrade to Mountain Lion

My personal laptop is a late 2009 Macbook Pro with 4GB of RAM, 250GB hard drive, 2.53 GHz Intel Core 2 Duo, making it 7 years old at the time I’m writing this post. As Apple released updates over the years, like anyone else I was always excited to try out the newest features and installed each one as soon as I could. However, as I upgraded, I noticed my laptop get progressively slower, until it was an absolute pain to use.\u00a0

The solution for me was to give up on the upgrades and downgrade\u00a0to Mountain Lion (10.8.5). My Macbook is now back in proper shape, running smoothly with no issues (it has been a couple weeks now). I will no longer upgrade past this version; I’m just using TIme Machine to back up my files to an external hard drive and will restore a previous backed up version if something happens in the future.

I’m not going to detail the reinstall here since there are so many tutorials online you can simply Google. But I will share my steps in a summarized way:

  1. Back up my files using Time Machine and an external drive
  2. Download Mountain Lion from the Mac App Store
  3. Download DiskMaker X (an older version of it) and made a bootable USB drive with Mountain Lion*
  4. Boot from the USB drive and follow the install prompts (restart and hold Option after hearing the startup sound)

If I recall correctly, I may have ended up using Disk Utility instead of DiskMaker X, after having some issues and looking up another install method. The page I found had me pull a folder from within the Mountain Lion install file and create a bootable disk with that. I’d try both if one way doesn’t work.

It took a handful of attempts to complete the install. It would stop in the middle, give errors, and I had to reset the PRAM a few times. Be persistent, and you’ll eventually figure it out. These laptops are too expensive to just throw away!

If you do have the same or similar year laptop, chances are you’re having battery issues as well. Check my post about changing your Macbook Pro’s battery.

Copyright © 2020 Andrew Delos Reyes. All rights reserved.