Fresh install of Mountain Lion

[AppleFan115]

Once I download Mountain Lion from the App Store, is the partitioned part of the hard drive that contains the necessary OS files (currently Lion) going to be rewritten, so I can freshly install Mountain Lion from that partitioned space? Or do I have to save Mountain Lion to a flash drive or disc and do a fresh install?
Thanks for your help!

 

[53kyle]

You have to copy to the flash drive. To do that, just right click the installer, navigate to Contents > SharedSupport and you should see InstallESD.dmg. Copy that to your desktop. Open disk utility and drag InstallESD.dmg to the sidebar. Click on the restore tab. Now insert your flash drive into your Mac and drag the InstallESD.dmg to the source box and drag the flash drive to the destination box. Finally hit restore and when it finished, boot holding the option key and select the flash drive. When you click the arrow under it, your Mac will start booting. Once it is done, click disk utility and then continue. Select your hard drive and click on the erase tab. Name it whatever you want and click erase. You can then quit disk utility and click reinstall os x mountain lion.

 

[Irock619]

Once I download Mountain Lion from the App Store, is the partitioned part of the hard drive that contains the necessary OS files (currently Lion) going to be rewritten, so I can freshly install Mountain Lion from that partitioned space? Or do I have to save Mountain Lion to a flash drive or disc and do a fresh install?
Thanks for your help!

You have to actually install ML to get the recovery partition on your drive. After that you can reboot holding command-R, then erase your drive, then download ML again for a fresh install.

 

[53kyle]

You have to actually install ML to get the recovery partition on your drive. After that you can reboot holding command-R, then erase your drive, then download ML again for a fresh install.

Doing it the other way makes less downloading and makes it so if your hd ever dies on you, you have a backup

 

[Irock619]

Doing it the other way makes less downloading and makes it so if your hd ever dies on you, you have a backup

It's common knowledge to always have a backup. I would backup to TM before even upgrading.