OK here goes, I'm currently running macOS Big Sur on a 21.5inch Late 2013 iMac (patched) but it's running slow and would like to revert to the latest OS for my iMac which I believe it's Catalina. I've attached a screenshot of the disk utility and would like some help on what to delete for a clean internet install of Catalina.
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Want to Factory Reset iMac but Need Some Advice
- Thread starter gibbothegreat
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In your title you specifically said "factory reset" -- if that's really what you want, than let me just state up front, quite clearly:
* * * This will delete everything. All gone. Zorched. Delorted! Buh-bye, precious data! * * *
So yeah... if there's anything at all on either your macOS partition or your Bootcamp partition that you want to retain, you should perform appropriate backups before doing this stuff. That said...
If you don't already have Catalina installed, I would recommend just doing that update from the Mac App Store first, as the final results should be cleaner.
Next, you need to boot from the Recovery Partition, by rebooting while holding down Command-R. (If you're using a wireless keyboard, you're probably going to have to scavenge up a wired keyboard to make this part work; wireless keyboards can't always get you there.) Once you've booted into Recovery mode, open Disk Utility, hit the "Erase" button at the top of that window and change the partitioning scheme to a single partition. This will merge that 400GB of Bootcamp partition space into the macOS partition, (giving macOS the full 1TB of space) and wipe whatever data you currently have on both partitions. Once you've completed the partitioning, you can exit Disk Utility and reinstall macOS from the Recovery Partition.
As an aside, you mentioned "internet install": I think you may be referring to the "macOS Recovery mode over the internet" option available via Command-Option-R on Macs which support that, but it has been my experience that using that mode doesn't actually pull down the latest compatible major version of macOS; it only pulls down the latest patch to the OS version which was most recently installed on that Mac, even if the hard drive has already been wiped. (Reason? Oh, I would guess it's something-something-firmware-something.)
* * * This will delete everything. All gone. Zorched. Delorted! Buh-bye, precious data! * * *
So yeah... if there's anything at all on either your macOS partition or your Bootcamp partition that you want to retain, you should perform appropriate backups before doing this stuff. That said...
If you don't already have Catalina installed, I would recommend just doing that update from the Mac App Store first, as the final results should be cleaner.
Next, you need to boot from the Recovery Partition, by rebooting while holding down Command-R. (If you're using a wireless keyboard, you're probably going to have to scavenge up a wired keyboard to make this part work; wireless keyboards can't always get you there.) Once you've booted into Recovery mode, open Disk Utility, hit the "Erase" button at the top of that window and change the partitioning scheme to a single partition. This will merge that 400GB of Bootcamp partition space into the macOS partition, (giving macOS the full 1TB of space) and wipe whatever data you currently have on both partitions. Once you've completed the partitioning, you can exit Disk Utility and reinstall macOS from the Recovery Partition.
As an aside, you mentioned "internet install": I think you may be referring to the "macOS Recovery mode over the internet" option available via Command-Option-R on Macs which support that, but it has been my experience that using that mode doesn't actually pull down the latest compatible major version of macOS; it only pulls down the latest patch to the OS version which was most recently installed on that Mac, even if the hard drive has already been wiped. (Reason? Oh, I would guess it's something-something-firmware-something.)
I believe the late 2013 iMacs shipped with Mojave, not Catalina.
Your screen capture shows SATA, meaning you have a mechanical hard drive. Mojave was the last OS to support Mac OS Extended as a file system. While APFS will work with mechanical hard drives, it wasn't written for them, thus it does degrade performance. APFS is best for SSD drives. Please note that the full Mojave installer will only format your drive in APFS, upgrading from High Sierra allowed you to keep Mac OS Extended as a base file system.
A factory reset, as mentioned above, literally returns your system to the setup that it shipped under. If you are looking to do a clean install, that is different. A clean install means installing the OS anew to an existing drive/partition. While both involve erasing any existing data, one is done machine wide whereas the other is done drive/partition wide. So for example if you wish to keep your existing bootcamp partition, you would want to do a clean install.
A clean install requires a bootable USB drive with the OS of your choice prepared for installation on it. There are many guides on how to do this. Keep in mind that Apple will remove older OSes from the App Store after a period of time, so you may or may not be able to find a copy of the OS installer to even make a bootable USB drive.
The key thing to remember here is that you will need to back up any data you wish to retain because it will be overwritten otherwise. You will want to note your passwords and preferences for various applications that you use. Mail server settings et al. These things are often not stored in the cloud, thus it is up to you to re-enter that information when reinstalling your applications and regaining internet access.
It really isn't as complicated as it may sound, but you have to do some prep work to make the process pain free.
support.apple.com
support.apple.com
Your screen capture shows SATA, meaning you have a mechanical hard drive. Mojave was the last OS to support Mac OS Extended as a file system. While APFS will work with mechanical hard drives, it wasn't written for them, thus it does degrade performance. APFS is best for SSD drives. Please note that the full Mojave installer will only format your drive in APFS, upgrading from High Sierra allowed you to keep Mac OS Extended as a base file system.
A factory reset, as mentioned above, literally returns your system to the setup that it shipped under. If you are looking to do a clean install, that is different. A clean install means installing the OS anew to an existing drive/partition. While both involve erasing any existing data, one is done machine wide whereas the other is done drive/partition wide. So for example if you wish to keep your existing bootcamp partition, you would want to do a clean install.
A clean install requires a bootable USB drive with the OS of your choice prepared for installation on it. There are many guides on how to do this. Keep in mind that Apple will remove older OSes from the App Store after a period of time, so you may or may not be able to find a copy of the OS installer to even make a bootable USB drive.
The key thing to remember here is that you will need to back up any data you wish to retain because it will be overwritten otherwise. You will want to note your passwords and preferences for various applications that you use. Mail server settings et al. These things are often not stored in the cloud, thus it is up to you to re-enter that information when reinstalling your applications and regaining internet access.
It really isn't as complicated as it may sound, but you have to do some prep work to make the process pain free.
Create a bootable installer for macOS - Apple Support
You can use a USB flash drive or other secondary volume as a startup disk from which to install the Mac operating system. These steps are primarily for system administrators and other experienced users who are familiar with entering commands in Terminal.
What to do before you sell, give away, trade in, or recycle your Mac - Apple Support
Reset your Mac to factory settings to prepare it for a new owner.
I'm not sure that's correct. I'm reasonably certain that if you already have an OS installed on your drive and perform a fresh installation from the Recovery partition on that drive, the results would be indistinguishable from installing from a USB containing the installer for that same version of the OS. Likewise for installing from the "Recovery over the internet" option -- except that the internet option should also pull down the latest patches.
I'm pretty sure that the primary reason you would want to use a USB installer is if you already have a completely empty hard drive on the target computer and either a) don't have access to the internet from the target computer, or b) need to clean off multiple computers. But I don't think any of that applies to the OP's use case.
Cant you just wipe the drive in disc utility and download the OS ? using cmd r when booting the machine ? And it should download what OS came with the machine right ?
OP has a 2.5-inch HDD. Nothing that you do with that hard drive will help much for speed, except upgrading to an SSD.
I just rebuilt that version 2013 iMac, added an m.2 blade SSD, which transformed that iMac. I also maxed out the RAM to 16GB (had 4GB before the upgrade). It's not an upgrade for the faint-of-heart, requires completely removing the logic board, the RAM and PCIe slots are both on the back -- but the results made it worth the effort.
I just rebuilt that version 2013 iMac, added an m.2 blade SSD, which transformed that iMac. I also maxed out the RAM to 16GB (had 4GB before the upgrade). It's not an upgrade for the faint-of-heart, requires completely removing the logic board, the RAM and PCIe slots are both on the back -- but the results made it worth the effort.
Weeeeeeelllll... no, not really -- at least, not always. When you update the OS on a Mac, Apple has often historically included a firmware update which limits and/or eliminates your ability to go backwards. It is of course meant to be a convenience, in that you can go forward more easily from that point without having to install multiple intermediary software updates... but it also technically eliminates your ability to perform a true factory reset and return to the originally installed OS, since your Mac can be rendered incompatible with that original OS.
I would speculate that it is probably rare for this to become an actual problem... but I obviously can't speak for everyone.
This is probably true -- but I didn't attempt to address it because it's not what the OP asked. (I know, I know... I'm too literal. My wife reminds me of that quite frequently. And no... her name isn't Amy. 🤓 )
I've not ever actually found an example of "limits and/or eliminates your ability to go backwards.
Always (at least until AS, or T1 chips), you just erase the boot partition, and reinstall whatever system is supported by that Mac. The key is erasing, reinstall or restore from your backup. You should be able to go back to whatever system you choose to install -- again, whatever system is supported on that Mac should work fine. No need to worry about some firmware update blocking you from installing a system that used to work. If that was the actual case, then this external drive that I use for booting just about every Mac. It has 13 full installs on separate partitions from Leopard to Monterey, and should refuse to boot certain Macs, but so far, all is good.
You can't reinstall an older system on top of a newer system to downgrade that system. Only erase will do the trick. That's nothing new, AFAIK, always been the story on a Mac with OS X/macOS
Always (at least until AS, or T1 chips), you just erase the boot partition, and reinstall whatever system is supported by that Mac. The key is erasing, reinstall or restore from your backup. You should be able to go back to whatever system you choose to install -- again, whatever system is supported on that Mac should work fine. No need to worry about some firmware update blocking you from installing a system that used to work. If that was the actual case, then this external drive that I use for booting just about every Mac. It has 13 full installs on separate partitions from Leopard to Monterey, and should refuse to boot certain Macs, but so far, all is good.
You can't reinstall an older system on top of a newer system to downgrade that system. Only erase will do the trick. That's nothing new, AFAIK, always been the story on a Mac with OS X/macOS
All my macs are mojave or earlier -- i wonder if thats way. i feel like ive forsure i was able to install the shipped OS after zeroing out the drive in disc utility. i refuse to update beyond mojave on my current macs haha
I will admit that it has been awhile since I've even attempted to go backwards, but I do specifically remember instances when a mandatory firmware update took place during an OS update, which prohibited me from subsequently reverting to any older OSes from that point forward.
That said... I'm a bit of an old timer. 👴 I also remember Guy Kawasaki's Evangelist emails, the "Pacman" cartoon and the Knight Rider series. (As bizarre and unbelievable as this seems in retrospect, I even remember actually enjoying Knight Rider, at the time.)
So my memories of some aspects of the Mac experience might very well be from before some of you (ahem) "kids" started using Macs. Take them for what they're worth.
Oh... and get off of my lawn! 😁
I had my Commodore 64, where I learned basic language in the '80s -- but technology, when I was in school, meant you knew how to use a slide rule, and you lived out of a CRC math tables book, loaded with sines, cosines, log tables, all that other "math-y" stuff. First Mac that I used was a Mac IIsi, but the first purchase was a Quadra 605, new, when I started working for an AASP (1993, 2 years after retirement from US military -- I also have been around for a bit!
Just as an amusing comparison:
- Learned BASIC on an Atari 800XL (Newer than your C64)
- First Mac used: SE-30 (Older than the IIsi -- learned how to program Hypercard on it!)
- First Mac owned: LC II (Older than the Q605)
- You: definitely older than me... as I graduated from highschool in '93. No slide rules for me!
(Kind'a peculiar that you never encountered the firmware issue I described, though. Differences between the various models we each used, over the years?)
I presently have about 10 different Macs, oldest is a 2000 G3 iMac, up to a 2017 MBAir, couple of minis, a titanium G4 MBPro, a 2008 iMac, 2011 iMac, eMac USB 2.0, a couple of others - and do some part-time Mac service for a local PC shop. I can say that I have never seen a Mac yet that I couldn't take back to the original system version. Exception to that would be some of those Macs that came with special versions of Tiger, for example, as you would need the DVD that shipped with that particular Mac to get the original shipping system.
I will say that I have read stories about some firmware updates that would prevent going back to older systems, but I have never seen an actual example of that. (I have not installed anything older than Tiger for probably 10 years, so maybe in one of those before Tiger -- maybe.
I will say that I have read stories about some firmware updates that would prevent going back to older systems, but I have never seen an actual example of that. (I have not installed anything older than Tiger for probably 10 years, so maybe in one of those before Tiger -- maybe.