What does reinstalling mountain lion do

It includes information on the decisions you make when performing a clean install. If you're going to install Mountain Lion on your Mac's startup drive, you must first restart your Mac from a bootable copy of the installer because the startup drive is erased before you perform the installation. Do this using Disk Utility, which is included with the installer. Insert the bootable media or connect it to your Mac and then restart the Mac while holding down the Option key.

This causes the Mac to display its built-in startup manager, where you select the device you want to boot from. Use the arrow keys to select the bootable Mountain Lion installer you created earlier, then press the Enter key to start the boot process. This is why you made your own bootable media. Select Disk Utility from the list of options, then select Continue. Select your Mac's startup volume from the list of devices in Disk Utility.

If you never changed its name, the startup volume is listed as Macintosh HD. Give the startup drive a name or use the default name, then select Erase. Your computer's eligibility must be verified before you can download and restore OS X. This happens because the bootable media you created does not contain all the files necessary for the install. The installer checks for any missing or new files it needs, downloads the files from Apple's servers, and then starts the installation process.

Select Continue. Read through the license agreement or don't , then select Agree. Select Agree once more to confirm. The installer displays a list of drives on which you can install Mountain Lion. Select the target drive the startup drive you erased earlier , then select Install. The installer checks the Mac App Store for updates and any other files it needs.

The installer copies the necessary files to the target disk and restarts the Mac. The on-screen prompts provided by the installer take you through most of it, but there are a few tricky spots. When your Mac reboots, a progress bar displays the time remaining in the installation. The time varies depending on the device, but it should be relatively short—less than 30 minutes in most cases.

When the progress bar hits zero, your Mac automatically restarts, and you are prompted for information. After restarting, your Mac starts the system setup process, including creating an administrator account and creating an iCloud account if you don't already have one.

Select your country from the list on the Welcome screen, then select Continue. Select your keyboard layout from the list, then select Continue. Choose whether to transfer user data, applications, and other information from another Mac, PC, or hard drive. You can also choose not to transfer data now.

Select Not Now. You can transfer data later using the Migration Assistant included with Mountain Lion. This way, you can ensure that your Mac is up and running without any problems before committing to the lengthy process of transferring data. Make your selection, then select Continue. Choose whether to enable location services. This feature allows your apps to figure out your approximate location and then use that data for various purposes, including mapping, advertising, and device location.

You can enable location services at any time, so you don't have to decide now. The installer asks for your Apple ID. You can skip this step if you'd like, but if you supply the information now, the installer configures iTunes, the Mac App Store, and iCloud. Incompatible software warning : If you upgraded a Snow Leopard or Lion Mac, the first time you boot into Mountain Lion you may see a dialog box informing you that some of the existing software on your Mac is incompatible with the new OS, and listing that software.

Apple provides more information about such software in a support article. In either case, OS X automatically moves this incompatible software to a folder called Incompatible Software at the root level of your startup drive. You may find, despite your pre-installation checks , that some of your existing software needs updates. Even if no updates to Mountain Lion itself are available, you may find that, after installing OS X Choose one, and OS X will see if drivers are available.

Click Add to download it and add this printer. Thanks to Macworld contributor Joe Kissell for this tip. If any of these services have been disabled, and you want to use them, turn them on now. For most people, Mountain Lion—like Lion before it—is easy enough to get and easy to install. But, also as with Lion, upgrading to OS X Even worse, if your ISP enforces caps on your Internet-data usage, you could end up paying a hefty price for the privilege.

I suspect that will continue to be the case with Mountain Lion. Businesses, schools, and other organizations and institutions that need to install Mountain Lion on many different computers : When Lion was released last year, we heard concerns from large installations—schools, businesses, and the like—about the Mac App Store-only distribution.

Posted on Feb 6, PM. Page content loaded. Selection A should be used on computers that came with Lion or later when factory new. These models had no disks included when new. Selection B is for Macs that came originally with Snow Leopard or earlier. These models shipped with Software Restore disks when new. Factory reset of your Mac - Apple Support. Feb 6, PM. Thank you for your quick response Kappy.

Seems I'm in between both of your solutions. If it did come with Snow Leopard, how would I know that? It did not come with any discs. No discs. I've had the same results "unavailable, please try again later". Model A, dated , purchased Is there a way to know if it came with Mountail Lion vs.

Snow Leopard by model number alone? If it was Snow Lepoard and I have no discs, what are the alternatives to getting any OS installed so I can then work on updating them? The model originally came with a special version of The retail copy of the You need the original DVDs that came with the computer when it was new.

It did have disks. All you could do is reinstall whatever version of macOS was installed before you erased the drive, and only if you did not end up erasing the Recovery HD that may have existed. The computer you have came to you used. You are not even the original owner of the macOS that was installed meaning you could not legally upgrade macOS.