Apple Computer Won't Boot to Login Screen

Follow these steps if your Apple computer won't boot or start to your login screen. Always consider hiring a professional. We are not responsible for loss of data or computer damage when you follow these steps.

If your Mac is stuck on the Apple logo

If you think you've waited long enough to know that your Mac is stuck on this screen, follow these steps.

Some of the fixes below are extreme. Make sure you have a backup and consider hiring a professional such as myself. See my article first on MacBook Pro Keeps Restarting 8 Ways to Fix Random Restarts. Some of the fixes such as resetting NVRAM or PRAM should be done first.

Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off. (Every Mac has a power button. On notebook computers that have Touch ID, press and hold Touch ID.)

Turn your Mac back on. If the issue persists, press and hold the power button until your Mac turns off. Then unplug all accessories from your Mac, including printers, drives, USB hubs, and other nonessential devices. You could have an issue with one or more of those devices or their cables.

Turn your Mac back on. If the issue persists, press and hold the power button once again until your Mac turns off. Then follow the steps in the section on howow to repair a Mac disk with Disk Utility. It explains how to start up from macOS Recovery so that you can use Disk Utility.

How to repair a Mac disk with Disk Utility

Use the First Aid feature of Disk Utility to find and repair disk errors.

Disk Utility can find and repair errors related to the formatting and directory structure of a Mac disk. Errors can lead to unexpected behavior when using your Mac, and significant errors might even prevent your Mac from starting up completely.

Before proceeding, make sure that you have a current backup of your Mac, in case you need to recover damaged files or Disk Utility finds errors that it can't repair.

Open Disk Utility

In general, you can just open Disk Utility from the Utilities folder of your Applications folder. However, if your Mac doesn't start up all the way, or you want to repair the disk your Mac starts up from, open Disk Utility from macOS Recovery:

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon: Turn on your Mac and continue to press and hold the power button until you see the startup options window. Click the gear icon labeled Options, then click Continue.

Intel processor: Turn on your Mac, then immediately press and hold these two keys until you see an Apple logo or other image: Command (⌘) and R.

You may be asked to select a user you know the password for. Select the user, then click Next and enter their administrator password.

From the utilities window in macOS Recovery, select Disk Utility and click Continue. macOS Recovery options with Disk Utility selected

Select your disk in Disk Utility

Choose View > Show All Devices (if available) from the menu bar or toolbar in Disk Utility.

Disk Utility: Show All Devices

Repair volumes, then containers, then disks

For each disk that you're repairing, start by selecting the last volume on that disk, then click the First Aid button or tab.

Click Run to begin checking the selected volume for errors.

If there is no Run button, click the Repair Disk button instead.

If the button is dimmed and you can't click it, skip this step for the disk, container, or volume you selected.

If you're asked for a password to unlock the disk, enter your administrator password.

After Disk Utility is done checking the volume, select the next item above it in the sidebar, then run First Aid again. Keep moving up the list, running First Aid for each volume on the disk, then each container on the disk, then finally the disk itself.

Disk First Aid: process complete

When you're done, quit Disk Utility. If you used Disk Utility from macOS Recovery, you can now restart your Mac: choose Apple menu > Restart.

If Disk Utility found errors that it can't repair

If Disk Utility found errors that it could not repair, use Disk Utility to erase (format) your disk.

Use Disk Utility to erase an Intel-based Mac

How to erase (format) built-in startup disk of an Intel-based Mac.

These steps do not apply to Mac computers with Apple silicon. If you're using a Mac with Apple silicon, follow the steps to erase a Mac with Apple silicon.

Before erasing your Mac

If using macOS Monterey or later on a Mac with the Apple T2 Security Chip, follow the steps to erase all content and settings instead of these steps.

Make a backup of any files that you want to keep. Erasing your Mac permanently deletes its files.

Use Disk Utility to erase your Mac

Start up from macOS Recovery: Turn on your Mac, then immediately press and hold these two keys until you see an Apple logo or other image: Command (⌘) and R.

If asked, select a user you know the password for, then enter their administrator password.

From the utilities window, select Disk Utility and click Continue.

Select Macintosh HD in the sidebar of Disk Utility. Don't see Macintosh HD? Click the Erase button in the toolbar, then enter the requested details:

Name: Macintosh HD

Format: APFS or Mac OS Extended (Journaled), as recommended by Disk Utility

Click Erase Volume Group. If this button isn't shown, click Erase instead.

Disk Utility window showing Erase volume group confirmation

If asked, enter your Apple ID.

Optional: If you previously used Disk Utility to add internal volumes other than Macintosh HD, you can erase them individually using the same process.

When you're done, quit the Disk Utility to return to the utilities window.

If you want your Mac to start up again from the volume you just you erased, select Reinstall macOS in the utilities window, then click Continue and follow the onscreen instructions. Learn more about reinstalling macOS.

If you don’t see Macintosh HD in Disk Utility

Your built-in startup disk should be the first item listed in the Disk Utility sidebar. It's named Macintosh HD, unless you changed its name. If you don't see it there, choose Apple menu > Shut Down, then unplug all nonessential devices from your Mac and try again.

If your disk doesn't appear in Disk Utility

If Disk Utility can't see your disk, it also can't see any containers or volumes on that disk. In that case, follow these steps:

Shut down your Mac, then unplug all nonessential devices from your Mac. If you're repairing an external drive, make sure that it's connected directly to your Mac using a cable that you know is good. Then turn the drive off, wait 30 seconds, then turn it back on.

If Disk Utility found no errors, reinstall macOS.

Make this a last resort and make sure your files and photos are backed up. Also make sure you know all your passwords. You might want to hire a professional to do this.

If Disk Utility found errors and repaired them, restart your Mac. If the issue returns after restarting, reinstall macOS.

MacBook Pro Keeps Restarting 8 Ways to Fix Random Restarts

Obviously, the easiest way to troubleshoot your MacBook Pro is to hire me and have me make a house call. I cover Honolulu Hawaii and all of Oahu. Text or call Rick Kirkham at 808.224.170 to check my availability.

8 - Perform Software updates on your Mac

As an in home computer tutor here in Honolulu Hawaii covering all of Oahu, I’m constantly seeing ignored updates from Apple computers.

7 - Reset NVRAM or PRAM

  • Shut down the computer.
  • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step
  • Turn on the computer.
  • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
  • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  • Release the keys.

6 - SMC Reset

  • Shut down the computer.
  • Unplug it from the wall.
  • Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
  • On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
  • Release all the keys and the power button at the same time.
  • Press the power button to turn on the computer.

5 - Reset disk permissions

The Repair Disk Permissions function—the process that actually performs the task of repairing permissions—examines certain files and folders on your Mac’s hard drive to see if their current permissions settings are what Mac OS X expects them to be; if discrepancies are found, the offending permissions are changed to match the expected settings.

For OSX Yosemite and older versions

  • Press "Cmd + R" on your keyboard to restart the Mac.
  • Open the Disk Utility feature.
  • Now choose "First Aid,"
  • "Repair Disk Permissions."

For MacOS Sierra or OSX El Capitan

  • Launch CleanMyMac X.
  • Choose the Advanced Maintenance option.
  • Complete repairing the disk permissions.

4 - Free up disk space

Ideally, you should have at least 20% of your total disk space free to prevent kernel panic. This is due to having low physical and virtual memory, which your Mac needs to run efficiently.

  • Go to the Apple Menu and choose "About This Mac."
  • Click on the "Storage" tab to see how much free storage you have.
  • If it is low, then you need to delete unnecessary files, such as pictures or videos.
  • You may also run CleanMyMac X to free up more space.

3 - Use the Disk Utility feature

  • Click on the Apple menu
  • Click "Restart."
  • Immediately hit the "Cmd + R" keys on your keyboard once the Mac restarts.
  • Click "Disk Utility."
  • Click “"First Aid."
  • Follow the on-screen prompts to find and fix errors on your Mac.

2 - Disable unnecessary startup items

At times, some startup tools which you do not need serve to clog up your Mac processor. This may make it sluggish, leading to a "Your Computer restarted Because of a Problem" error.

  • Select the Apple menu
  • Click "System Preferences."
  • Choose "Users & Groups"
  • Click your user account from the list.
  • Click on the "Login Items" tab to get a list of startup items.
  • Choose the startup item that you want to stop
  • Click "-." the minus sign on your keyboard
  • Now restart your Mac, and the kernel panic issue should be solved.

NOTE: To determine which startup program is causing the kernel panic, you should disable each one at a time before rebooting the Mac. Sometimes the problem may be due to a single item, which means you do not have to disable all of them.

1 - Repair corrupt MacOS files

At times, the kernel error is caused by corrupted MacOS files. The only way to fix this issue is to reinstall the macOS version that you are using.

  • Make sure you have an up-to-date backup from Time Machine or a third-party backup program.
  • Shutdown and restart your Mac and then Hold the "Cmd + R" keys to enter the "MacOS Utilities" feature.
    • Now select "Reinstall OS X" or "reinstall MacOS," depending on the version you are using. Once the OS has been reinstalled, restart your computer once again.

If none of those troubleshooting techniques work you have a hardware issue. Take your computer to a reputable computer repair shop.

One more piece of advice. Treat your computer more like a car than a refrigerator. In other words have me or someone like me clean and optimize your computer every four months. It will keep the computer fast and extend the life of the computer. House calls here in Honolulu Hawaii covering all of Oahu are available for this as well as remote help for the English speaking mainland U.S.A.


J. Richard Kirkham B.Sc.

The MacBook Pro link is an affiliate link which helps to support my efforts. It costs you nothing to click on and nothing extra when you order. Thank you for your support!

Repairing The Master Boot Record on Windows 10

Repairing the master boot record if your computer is in a repair loop or won't start. I highly advice having a computer repair professional do this for you. Honolulu Hawaii and all of Oahu text or call 224-1870

To fix MBR problems on a computer running Windows 10, use these steps:

Create a Windows 10 USB bootable media.

Change the boot order to start from the bootable media. The process to change the settings for the Basic Input Output System (BIOS) or Unified Extensible Firmware Interface (UEFI) usually requires pressing one of the function keys (F1, F2, F3, F10, or F12), the ESC or Delete key. However, the process is usually different per manufacturer and device model. Check your manufacturer’s support website for more specific instructions.

Start the PC with the bootable media.

Click the Next button in the Windows 10 Setup.

Click the Repair your computer button from the lower-left corner. Click the Troubleshoot button.

Click the Advanced options button.

Click the Command Prompt button.

You will now enter into the Command Prompt environment, which will allow you to launch the Bootrec.exe tool to repair the Master Boot Record on your Windows10 PC. The Bootrec.exe supports many options depending on your situation.

Use the FixMbr option when you need to repair Master Boot Record corruption problems or when you need to clean the code from the MBR. This command will not overwrite the existing partition table in the hard drive. Bootrec /fixMbr

Use the FixBoot option when the boot sector was replaced with another non-standard code, the boot sector is damaged, or when you installed an early version of the operating system alongside another more recent version. Bootrec /fixBoot

Use the ScanOS option when the Boot Manager menu does not list all the operating systems installed on your device. This option will scan all drives to find all compatible installations, and it will display the entries that are not in the BCD store. Bootrec /ScanOS

Use the RebuildBcd option when you don’t have another option, and you must rebuild the BCD (Boot Configuration Data) store. Bootrec /RebuildBcd

How To Fix Bootrec /fixboot Access is Denied During Fix Boot Configuration in Windows 10

While fixing the Boot Configuration Data (BCD) on your computer you may encounter the “Access is denied '' message in the command prompt window. If you are seeing this message you won’t be able to fix the boot related issue unless you take care of the problem first. To do so, follow these simple steps on your computer-

Recreate EFI structure and reconfigure the boot files

Recreating the EFI structure will help you to solve this issue.

First, turn off your computer.

After that, switch ON your machine.

Then, when your system starts up, as soon as you have seen the manufacturer’s logo, press-hold the power button again to force the shutdown of your system.

Continue these steps 2-3 more times and it will automatically reach the startup repair screen.

When your computer boots up, you will be in Automatic Repair mode. Click on the “Advanced options“.

In the Choose an option window, click on “Troubleshoot“.

In the Troubleshooting window, click on “Advanced options“.

In the Advanced_ options_ window, click on “Command Prompt“.

In the Command_ Prompt_ window, copy-paste these two commands one-by-one and hit Enter to execute both of the commands sequentially on your computer.


list disk

Again copy-paste and modify these commands in Command Prompt window one-by-one and hit Enter after each of them.

select disk your disk no

list vol

NOTE– Replace the “” with the number of HDD drive on which the Windows is installed.

For this computer, it is “Disk** 0**“. So the command will be like this-

** select disk 0**

Again copy-paste this command in Command Prompt and then hit Enter to select the System reserved volume.

select vol

[NOTE– Replace the “” which is declared to have 100 MB storage. This partition contains the EFI (Extensible Firmware Interface) and usually formatted in FAT32 format.

Example- For us, it is ‘Volume 5 **which is the FAT32 partition, and its size is limited to 100 MB**. So the command will be –

**select vol 5 **

Now, you have to assign a new drive letter to the partition. Copy-paste this command in the Command_ Prompt_ window and hit Enter to do so.

assign letter=V:

Upon completion, you will see this message – ‘diskpart successfully assigned the drive letter’.

In order to exit the diskpart, type this command and press Enter.


Now, type the command


After that run the command given below.

bcdboot C:windows /s V: /f UEFI

Close Command Prompt window.

Coming back to the Troubleshooting window, click on “Continue” to normally boot into Windows 10.

If this doesn't fix the problem you may need to reinstall Windows. Back up your files first. Consider a Windows Operating System alternative Linux Mint (video tour) which doesn't have problems like these.

All My Files Are Gone After a Windows 10 Update! 2021

All My Files Are Gone After a Windows 10 Update! 2021

When an in home computer client called in Honolulu Hawaii telling me all his files were gone after a Windows update, I knew it was either a coincidence and he had a computer virus or Microsoft was keeping their track record of releasing bad updates. Either way I told him not to touch the computer until I got there. If you're on Oahu for a computer repair house call or anywhere in the United States and speak English and choose NOT to have a professional computer repair technician handle this such as myself, I am NOT responsible for any damage you cause by getting into your Windows registry.

I would consider STOPPING right now trying to fix your own computer and texting me at 808.224.1870 so that I can help you with a housecall or remotely.

You May Find This Video Helpful If You’re Going Against My Advice and Not Calling a Professional.

Remember, the registry is the brains of your computer. You really should call a tech. NOT someone who knows a little more about computers than you do - A TECH!

To be clear this is not my video.

Directions on Fixing Your Own Computer’s Bad Profile and Loss of Files Against My Recommendation of Not Calling a Professional

Press Windows Key + X. Click on Powershell or type cmd in the search at the bottom of your screen.
Right mouse click on Command Prompt
Left click on Run as Administrator

In the black window, type the following command and press Enter.

net user Administrator /active:yes

I didn't find this necessary but the directions are there if you need them.

Now log off or restart your computer if you had to create the admin profile. On the log in screen, a new account named Administrator will now appear. Log in through it.

Correcting The Registry Entry

Log in through the built-in Administrator account if the one your on won't let you. Sometimes temp profiles are restricted.

Press Windows key + R. In the run window, type regedit and press Enter. Click Yes if the UAC warning appears.

In the left pane go to

HKEY_LOCAL_MACHINE-SOFTWARE-Microsoft-Windows- NT-CurrentVersion-ProfileList

Or just press Ctrl f on the keyboard and type in profilelist

Under ProfileList in the left pane, locate the SID keys which are something like “S-1-5-21..blah blah. You will see two or more of these SID keys

Find the profile that has a Ref count. It will probably be one.

Double click on Ref count

Set it to 0


Now check for Windows updates

Start>Settings>Windows Update

Run it even if it says it’s updated to date. The bad update may have been repaired.

Restart the computer

That fixed the profile for my in home computer client in Honolulu.

If that fixed it you’re done. Send me One million dollars so I can retire.

If You Still Don’t Have Your Files from The Bad Windows Update

Go back into the registry to the same place HKEY_LOCAL_MACHINE-SOFTWARE-Microsoft-Windows- NT-CurrentVersion-ProfileList

One Profile will have .bak at the end. The one with .bak is the link to your inaccessible profile and there will be one other that is to the temporary profile you are currently using.

Rename those keys by giving them the .bak ending by right mouse clicking on them. Remember what I tell my in home and remote computer tutoring students - “Right mouse click for a menu. Left mouse click for an action.” Many of my peers recommend deleting these keys. I tend to be cautious in deleting items in the Registry.

Right click on the “S-1-5-21…blah.bak and delete “.bak” from the end of the key. NOT THE KEY JUST .BAK. Close the window. Restart your computer.

If that doesn’t work, stop trying to do it yourself before you completely screw up your computer. CALL SOMEONE!

When You’re Finished Successfully Troubleshooting Your Computer

Press Windows Key + x or right mouse click on Start (Windows logo). Click on Command Prompt (Admin).

In the black window, type the following command and press Enter.

net user Administrator /active:no
This removes the Admin profile. I usually make sure my in home computer clients have two profiles for emergency access. 

My In Home Computer Client's Files Were Still Not There!

In this case they had been deleted by the Microsoft update. It's happened before. Fortunately he had found them before the update deleted them and backed them up to an external hard drive.

THIS brings up the importance of regular backups. If you're running a business, I highly recommend a 30 day FREE trial of Dr. Backup. A peace of mind managed backup service for both you and your clients' data.

If you're a computer user. Download my backup program I wrote using all native functions built into Windows so there would never be a block by antivirus software.

Remember, all computers and devices crash. Are you prepared?

Final Bit of Advice

Don’t play catch up with something as important as your computer files and photos. Have me clean and optimize your computer every four months to keep it running fast and efficient. I’ll see things and catch things before you see them.

Enjoy your computer,


J. Richard Kirkham B.Sc.

Mobile Computer Support for Oahu

Remote Computer Support for The English Speaking United States