1. Boot from Lion USB Install Disk
2. Pick Disk Utility to reformat
3. Select disk and Erase
4. Quit Disk Utility, Run Lion installer
5. Install runs after restart
Install took under 30 min
How To Clean Install Mac OS X Lion.
Maybe it’s a bit OCD, but doing a clean install of a new OS can be a good practice. In a lot of ways it’s like having a new Mac again.
By doing a clean install you reduce the chance of running into incompatibility issues with previously installed software. It also removes old outdated software and files that just take-up space and clutter your filesystem.
I usually reformat my hard drive while I’m at it. This will take care of any data corruption and disk errors that may exist and also removes fragmentation…
With Lion instead of buying a physical disc you download it from the Mac AppStore inside of Mac OS Snow Leopard so by default it will upgrade your system and you are unable to reformat your drive because the installer is on the same drive.
You can easily make yourself a bootable install disk that will allow you to reformat your drive.
Don’t forget to backup your data before reformatting! You’ll want at least your documents, music, and photos after the reformat and install.