Can’t reinstall Lion or erase disk

nathan_1985 Said:

"Can’t reinstall Lion or erase disk: I’ve tried booting with Command-R and erasing disk but the erase option is grayed out. I’ve tried reinstalling Lion but my disk is not visible to start the reinstall. I previously updated to Mojave (which was a bad decision because my computer has been very slow). Lastly there is only 38.3 mb of available space, yes only 38.3 mb!! I did not know it was that close. Please help."

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If It will Not Interoperate:

1. Mount the Disk:

In Recovery Mode, do you see the "Mount" button available to click? If it reads "Mount", then click it to mount it. From there, click erase.

Once Mounted...

2. Use the "First Aid" Button:

While in Recovery Mode Also, select the hard drive, and then click First Aid button. From there, run First Aid on the drive.

From there...

3. Reinstall the macOS Anew:

Perform the following in the order provided:

I. If it applies: Back up your Mac with Time Machine - Apple Support

Then...

II. Reinstall the macOS Anew:

1. Boot: into Recovery Mode.
2. Open: Disk Utilities
3. Delete: the partition
4. Reinstall: the macOS

Once Installed Anew...

III. Reinstall All the Software:

1. Use Migration Assistant to move Apps a Files back in.
2. Ask developers for new software keys - but contact the developers only --- none other --- or you may end up with malware and spyware installed.

When you are in Recovery Mode and have Disk Utility open click on View in the menubar and select Show All devices.

Now post a screenshot of what you see there.

Many people are finding it difficult to reinstall Mac OS X Lion installed on their macs using Apples Recovery servers.

Does your Mac still have an OS on it, and is operable, if so have a look at some other options.

If your mac can run Lion and Mojave then it can run El Capitan or High Sierra.

You can download either of these and create a bootable USB installer.

Use Safari to click on these links,

How to upgrade to macOS High Sierra - Apple Support

How to upgrade to OS X El Capitan - Apple Support

For El Capitan.

Go to Section 4 and click on Download OS X El Capitan.

This downloads InstallMacOSX.dmg to your Downloads folder.

When downloaded open to InstallMacOSX.pkg, double-click on

that and an installation window will open, this does not install El Capitan

but converts the .pkg to the Install OS X El Capitan.app which you will find in 

your Applications folder, it should be 6.2GBs in size.

For High Sierra

Go to Section 4 and click on Get macOS High Sierra.

This will download Install macOS High Sierra.app into your Applications folder.

Now make a bootable USB installer, How to create a bootable installer for macOS – Apple Support

Before downgrading make a full back up of your Mac.

After you have created your back up boot back to your Recovery HD

open Disk Utility, make sure Show All Devices is selected.

Click on the uppermost disk in the left hand panel.

Click Erase.

Name: give your disk a unique name.

Format: Mac OS Extended (Journaled) - if you are installing El Capitan or

APFS - if you are installing High Sierra.

Scheme: GUID Partition Map

Click Erase.

Once that has completed you can quit Disk Utility.

Plug the bootable USB into your mac.

Restart the mac while pressing and holding the option/ alt key

in a couple of minutes you should see the Startup Manager,

select the USB and press Return.

The mac will now boot to the USB, when it does you will see a

Utilities panel, click on Install OS, press Continue.

The installer app should start up, follow the prompts.

When that completes and you have gone through the set up process

you can now move back your personal data/ files from your back up.

do not migrate any System or Library settings as this will put Mojave back on your mac.

If you really have run your mac down to 38MBs of free space, it would be pretty unusable,

in fact it should have locked up. Always keep between 15-20GBs of free space, the mac needs room to breathe

as it is constantly writing and organising its System.