TABLE OF CONTENTS

• How Windows Boot
• Copyright And Permissions
• Creating Windows Repair Disk
• How To Fix Windows Blue Screen Of Death
• How To Fix Rebooting Windows
• How To Fix Windows Black Screen Of Death
• Unbootable Windows Hardware Problems
• How To Fix Infinite Loading Screen

How the Windows System Boots

When you power any PC on, the Basic Input Output System (what’s a BIOS?) or Unified Extensible Firmware Interface (what’s a UEFI?) determines which partition to load, based on data it reads from the boot loader. In older Windows systems, we refer to the boot loader as the Master Boot Record (MBR). In Windows 10 the new boot loader is referred to as a GUID Partition Table (or GPT), although users can still employ the older MBR.Depending on your system’s age, you might have either a BIOS or UEFI, which facilitates the loading of your boot loader. Newer systems rely on an UEFI, whereas older systems use the BIOS.

If either the MBR, GPT or core operating system drivers become damaged, you will experience an unbootable system. The difference between the two lies in the initial symptoms experienced by your computer while it boots. If you get a blue screen, that probably means the MBR or GPT successfully loaded and it failed to complete boot-up. If you get some other condition, like a blinking cursor amid the blackness of a DOS prompt, then the MBR/GPT might be damaged.

For the majority of boot problems, the Windows System Repair Disk provides the easiest solution.

Copyright And Permissions

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or be transmitted, in any form, or by any means, mechanical, electronic, photocopying or otherwise without the prior written consent of the publisher: It is protected under the copyright laws.

Creating a Windows System Repair Disk

Making the repair disk just requires another Windows (7, 8, or 10) machine and a USB drive with at least 128MB of storage. Once you have the two, insert the USB drive and search for Create a recovery drive.

After selecting the program, and clicking through a confirmation window, choose the flash drive as your target for the recovery  drive and select next.

Click through the next few windows. Your flash drive will be formatted, so make sure there’s nothing you can’t lose stored on it.

After the format finishes, you can then boot from the USB drive as if it were a DVD. You will use this disk to repair or diagnose your operating system. Here’s how to boot from a USB drive.

You will then need to restart your computer and boot from the Windows System Recovery Disk. Successfully booting from this disk varies from PC to PC. Most of the time, pressing a F10, F11, or F12 on boot will give you the option of booting into the drive’s recovery system. If you don’t know, try an Internet search for “USB boot” + your model of computer. For example, if you have a Dell XPS 13, search for the following:

“Dell XPS 13 USB boot”

Alternatively, you might need to enter your system’s BIOS. By pressing f10 Command.

How to Fix a Windows Blue Screen of Death

BSODs can occur because of either hardware or software problems. Although by far the most common cause originates in your operating system’s drivers. If there’s a damaged or missing driver which plays a key role in your system’s ability to boot, the entire system will fail to load.

So here’s what it looks like happened: You attempted to back up a partition on an Android smartphone and accidentally damaged Windows. Judging from the documentation for DiskGenius (which is now known as Partition Guru), it doesn’t seem likely that you erased any data storing partitions. If anything, it sounds like you’ve got some driver or hardware problems. We don’t know for certain though, so you’re going to have to do some sleuthing and troubleshooting.

Start off by plugging the error code or message from the Blue Screen of Death (BSOD) into a search engine. The BSOD should look something like this (except with a different error code):

So, to reiterate: Write down the error code.

Then shut the computer off and unplug everything that isn’t a power source or integral to the computer booting (like USB hard drives or external speakers). Then restart the computer. If the problem persists, then it’s not related to anything you had plugged into the computer. Next, boot into your Windows System Recovery Disk.

Once booted into the System Recovery Disk, choose the options Repair your computer and then Troubleshoot.

Then select Advanced options. In Windows 8, and 10 you have access to Automatic repair. The Recovery Disk should automatically repair any MBR or GPT faults. In Windows 7, you can choose to restore from a backup using System Restore or you can choose Startup repair (which is similar to automatic repair).

If this fails, you can also choose to refresh or reset your systeIf refreshing/resetting doesn’t work, . Keep in mind that choosing a refresh or reset will cause some data loss.

 but searching is always a good first step. If Google doesn’t provide any answers, I suggest attempting to reset or refresh your system using a Windows System Recovery Disk or a Windows (7, 8, 10) installation disk. We’ve covered in detail the steps required in making a Windows repair drive.

Fix Rebooting Windows

If Windows continuously reboots, in Windows 8 and above the operating system should automatically enter the System Recovery Options menu after the third forced reboot. Windows 7 and below will not do this automatically, which requires that the user manually tap F8 while booting. After tapping F8, Windows 7 (and Vista) will enter into the Advanced Startup Options menu.

Once inside the Advanced Startup Options menu, users can choose enter Safe Mode, restore to an earlier functioning state, and a more. Alternatively, they can enter the System Recovery Options menu, which works a bit like Windows 8 and 10’s recovery menu.

Here’s an excellent video on repairing a rebooting Windows installation:

Fix the Windows Black Screen of Death

There’s also the Black Screen of Death, which is far more difficult to resolve. Not only are there many different kinds of Black Screens of Death, there’s a variety of means to combat the problem. There’s two primary kinds of Black Screens: The blinking underscore and the black screen with a mouse cursor.

How to Fix Windows 10 Black Screen, Cursor

Windows 10 brings with it a new category of black screen Windows boot failures. Although technically, the machine did boot properly. The problem originates in the graphical drivers that Windows loads by default after installation. Windows 10 believes that it loaded the correct drivers, so the machine won’t automatically enter recovery mode.

Fix Windows Black Screen, Blinking Underscore

On boot, if your system displays a black screen with a blinking cursor, your hard drive isn’t detected properly. A common resolution entails heading into your BIOS or UEFI settings and toggling your drives connection standard from RAID or IDE mode to AHCI (or vice-versa). If that fails, you’ll want to change the boot order of your drives so that the drive containing the operating system shows up first in the boot order.

On Windows 7 (and older systems) sometimes changing your drive from IDE to AHCI will break your system. This requires installing a Microsoft Fix It executable, which adds AHCI compatibility to Windows 7.

Fix Windows Infinite Loading Screen

Windows can also enter an unbootable state where the Windows loading icon displays, but the system never boots. Sometimes this is caused by a flaky Windows update. Other times, it can show up out of the blue.

Unbootable Windows Hardware Problems

If your computer fails to pass Power On Self Test that definitely means a hardware failure has occurred. This article covers, how to deal with harware issues this method revolves around attempting to narrow the cause of failure down to an individual, defective component, which means unplugging all non-essential devices and attempting to boot the machine. It’s the most basic troubleshooting methodology and no hardware repair guide is complete without it. However, a motherboard’s complexity requires a special troubleshooting process.

I’ve covered troubleshooting motherboard problems and how they can cause unbootable system states. Essentially, when the motherboard’s firmware isn’t working properly, users can resolve the issue using a few simple troubleshooting methods. The most effective of these is the deep reset, which temporarily halts power to the volatile memory on board all computers, thus resetting it to a factory fresh state.

Unfortunately, many Ultrabooks (what’s an Ultrabook?) and laptops don’t allow easy access to the BIOS backup battery. In this case, you would need to contact a skilled technician for additional support.

So Where Does that Leave Us?

You might notice that most of the repair methods revolve around using the Windows Recovery Disk. There’s a reason for this: The Windows Recovery Disk can resolve most boot problems. But for the most part, you will need to familiarize yourself with the Repair Tool in order to maximize chances of booting your system again.

There are several reasons why a Windows-based computer may have problems during startup. To troubleshoot boot problems, first determine in which of the following phases the computer gets stuck:

Phase	Boot Process	BIOS	UEFI
1	PreBoot	MBR/PBR (Bootstrap Code)	UEFI Firmware
2	Windows Boot Manager	%SystemDrive%\bootmgr	\EFI\Microsoft\Boot\bootmgfw.efi
3	Windows OS Loader	%SystemRoot%\system32\winload.exe	%SystemRoot%\system32\winload.efi
4	Windows NT OS Kernel	%SystemRoot%\system32\ntoskrnl.exe

1. PreBoot: The PC’s firmware initiates a power-on self test (POST) and loads firmware settings. This pre-boot process ends when a valid system disk is detected. Firmware reads the master boot record (MBR), and then starts Windows Boot Manager.
2. Windows Boot Manager: Windows Boot Manager finds and starts the Windows loader (Winload.exe) on the Windows boot partition.
3. Windows operating system loader: Essential drivers required to start the Windows kernel are loaded and the kernel starts to run.
4. Windows NT OS Kernel: The kernel loads into memory the system registry hive and other drivers that are marked as BOOT_START.

The kernel passes control to the session manager process (Smss.exe) which initializes the system session, and loads and starts the devices and drivers that aren’t marked BOOT_START.

Here’s a summary of the boot sequence, what will be seen on the display, and typical boot problems at that point in the sequence. Before you start troubleshooting, you have to understand the outline of the boot process and display status to ensure that the issue is properly identified at the beginning of the engagement. Select the thumbnail to view it larger.

Each phase has a different approach to troubleshooting. This article provides troubleshooting techniques for problems that occur during the first three phases.

 Note

If the computer repeatedly boots to the recovery options, run the following command at a command prompt to break the cycle:

Bcdedit /set {default} recoveryenabled no

If the F8 options don’t work, run the following command:

Bcdedit /set {default} bootmenupolicy legacy

BIOS phase

To determine whether the system has passed the BIOS phase, follow these steps:

1. If there are any external peripherals connected to the computer, disconnect them.
2. Check whether the hard disk drive light on the physical computer is working. If it’s not working, this dysfunction indicates that the startup process is stuck at the BIOS phase.
3. Press the NumLock key to see whether the indicator light toggles on and off. If it doesn’t toggle, this dysfunction indicates that the startup process is stuck at BIOS.

If the system is stuck at the BIOS phase, there may be a hardware problem.

Boot loader phase

If the screen is black except for a blinking cursor, or if you receive one of the following error codes, this status indicates that the boot process is stuck in the Boot Loader phase:

• Boot Configuration Data (BCD) missing or corrupted
• Boot file or MBR corrupted
• Operating system Missing
• Boot sector missing or corrupted
• Bootmgr missing or corrupted
• Unable to boot due to system hive missing or corrupted

To troubleshoot this problem, use Windows installation media to start the computer, press Shift+F10 for a command prompt, and then use any of the following methods.

Method 1: Startup repair tool

The Startup Repair tool automatically fixes many common problems. The tool also lets you quickly diagnose and repair more complex startup problems. When the computer detects a startup problem, the computer starts the Startup Repair tool. When the tool starts, it performs diagnostics. These diagnostics include analyzing startup log files to determine the cause of the problem. When the Startup Repair tool determines the cause, the tool tries to fix the problem automatically.

To do this task of invoking the Startup Repair tool, follow these steps.

1. Start the system to the installation media for the installed version of Windows. 
2. On the Install Windows screen, select Next > Repair your computer.
3. On the Choose an option screen, select Troubleshoot.
4. On the Advanced options screen, select Startup Repair.
5. After Startup Repair, select Shutdown, then turn on your PC to see if Windows can boot properly.

The Startup Repair tool generates a log file to help you understand the startup problems and the repairs that were made. You can find the log file in the following location:

%windir%\System32\LogFiles\Srt\Srttrail.txt

Method 2: Repair boot codes

To repair boot codes, run the following command:

ConsoleCopy

BOOTREC /FIXMBR

To repair the boot sector, run the following command:

ConsoleCopy

BOOTREC /FIXBOOT

 Note

Running BOOTREC together with Fixmbr overwrites only the master boot code. If the corruption in the MBR affects the partition table, running Fixmbr may not fix the problem.

Method 3: Fix BCD errors

If you receive BCD-related errors, follow these steps:

1. Scan for all the systems that are installed. To do this step, run the following command:

ConsoleCopy

Bootrec /ScanOS

• Restart the computer to check whether the problem is fixed.
• If the problem isn’t fixed, run the following commands:

ConsoleCopy

bcdedit /export c:\bcdbackup

attrib c:\boot\bcd -r -s -h

ren c:\boot\bcd bcd.old

bootrec /rebuildbcd

• Restart the system.

Method 4: Replace Bootmgr

If methods 1, 2 and 3 don’t fix the problem, replace the Bootmgr file from drive C to the System Reserved partition. To do this replacement, follow these steps:

1. At a command prompt, change the directory to the System Reserved partition.
2. Run the attrib command to unhide the file:

ConsoleCopy

attrib -r -s -h

• Navigate to the system drive and run the same command:

ConsoleCopy

attrib -r -s -h

• Rename the bootmgr file as bootmgr.old:

ConsoleCopy

ren c:\bootmgr bootmgr.old

• Navigate to the system drive.
• Copy the bootmgr file, and then paste it to the System Reserved partition.
• Restart the computer.

Method 5: Restore system hive

If Windows can’t load the system registry hive into memory, you must restore the system hive. To do this step, use the Windows Recovery Environment or use the Emergency Repair Disk (ERD) to copy the files from the C:\Windows\System32\config\RegBack directory to C:\Windows\System32\config.

If the problem persists, you may want to restore the system state backup to an alternative location, and then retrieve the registry hives to be replaced.

 Note

Starting in Windows 10, version 1803, Windows no longer automatically backs up the system registry to the RegBack folder.This change is by design, and is intended to help reduce the overall disk footprint size of Windows. To recover a system with a corrupt registry hive, Microsoft recommends that you use a system restore point.

Kernel phase

If the system gets stuck during the kernel phase, you experience multiple symptoms or receive multiple error messages. These error messages include, but aren’t limited to, the following examples:

• A Stop error appears after the splash screen (Windows Logo screen).
• Specific error code is displayed. For example, 0x00000C2 , 0x0000007B , or inaccessible boot device.
• The screen is stuck at the “spinning wheel” (rolling dots) “system busy” icon.
• A black screen appears after the splash screen.

To troubleshoot these problems, try the following recovery boot options one at a time.

Scenario 1: Try to start the computer in Safe mode or Last Known Good Configuration

On the Advanced Boot Options screen, try to start the computer in Safe Mode or Safe Mode with Networking. If either of these options works, use Event Viewer to help identify and diagnose the cause of the boot problem. To view events that are recorded in the event logs, follow these steps:

1. Use one of the following methods to open Event Viewer:
   1. Go to the Start menu, select Administrative Tools, and then select Event Viewer.
   1. Start the Event Viewer snap-in in Microsoft Management Console (MMC).
2. In the console tree, expand Event Viewer, and then select the log that you want to view. For example, choose System log or Application log.
3. In the details pane, open the event that you want to view.
4. On the Edit menu, select Copy. Open a new document in the program in which you want to paste the event. For example, Microsoft Word. Then select Paste.
5. Use the up arrow or down arrow key to view the description of the previous or next event.

Clean boot

To troubleshoot problems that affect services, do a clean boot by using System Configuration (msconfig). Select Selective startup to test the services one at a time to determine which one is causing the problem. If you can’t find the cause, try including system services. However, in most cases, the problematic service is third-party.

Disable any service that you find to be faulty, and try to start the computer again by selecting Normal startup..

If the computer starts in Disable Driver Signature mode, start the computer in Disable Driver Signature Enforcement mode, and then follow the steps that are documented in the following article to determine which drivers or files require driver signature enforcement: 

If the computer is a domain controller, try Directory Services Restore mode (DSRM).

This method is an important step if you encounter Stop error “0xC00002E1” or “0xC00002E2”

Examples

 Warning

Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft can’t guarantee that these problems can be solved. Modify the registry at your own risk.

Error code INACCESSIBLE_BOOT_DEVICE (STOP 0x7B)

To troubleshoot this Stop error, follow these steps to filter the drivers:

1. Go to Windows Recovery Environment (WinRE) by putting an ISO disk of the system in the disk drive. The ISO should be of the same version of Windows or a later version.
2. Open the registry.
3. Load the system hive, and name it test.
4. Under the following registry subkey, check for lower filter and upper filter items for non-Microsoft drivers:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class

• For each third-party driver that you locate, select the upper or lower filter, and then delete the value data.
• Search through the whole registry for similar items. Process as appropriate, and then unload the registry hive.
• Restart the server in Normal mode.

To fix problems that occur after you install Windows updates, check for pending updates by using these steps:

1. Open a Command Prompt window in WinRE.
2. Run the command:

ConsoleCopy

DISM /image:C:\ /get-packages

• If there are any pending updates, uninstall them by running the following commands:

ConsoleCopy

DISM /image:C:\ /remove-package /packagename: name of the package

DISM /Image:C:\ /Cleanup-Image /RevertPendingActions

Try to start the computer.

If the computer doesn’t start, follow these steps:

1. Open a command prompt window in WinRE, and start a text editor, such as Notepad.
2. Navigate to the system drive, and search for windows\winsxs\pending.xml.
3. If the pending.xml file is found, rename the file as pending.xml.old.
4. Open the registry, and then load the component hive in HKEY_LOCAL_MACHINE as test.
5. Highlight the loaded test hive, and then search for the pendingxmlidentifier value.
6. If the pendingxmlidentifier value exists, delete it.
7. Unload the test hive.
8. Load the system hive, name it test.
9. Navigate to the following subkey:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\TrustedInstaller

1. Change the Start value from 1 to 4.
2. Unload the hive.
3. Try to start the computer.

If the Stop error occurs late in the startup process, or if the Stop error is still being generated, you can capture a memory dump. A good memory dump can help determine the root cause of the Stop error.

Sometimes the dump file shows an error that’s related to a driver. For example, windows\system32\drivers\stcvsm.sys is missing or corrupted. In this instance, follow these guidelines:

• Check the functionality that’s provided by the driver. If the driver is a third-party boot driver, make sure that you understand what it does.
• If the driver isn’t important and has no dependencies, load the system hive, and then disable the driver.
• If the stop error indicates system file corruption, run the system file checker in offline mode.
  • To do this action, open WinRE, open a command prompt, and then run the following command:

ConsoleCopy

SFC /Scannow /OffBootDir=C:\ /OffWinDir=C:\Windows.

• If there’s disk corruption, run the check disk command:

ConsoleCopy

chkdsk /f /r

• If the Stop error indicates general registry corruption, or if you believe that new drivers or services were installed, follow these steps:
  • Start WinRE, and open a command prompt window.
  • Start a text editor, such as Notepad.
  • Navigate to C:\Windows\System32\Config\.
  • Rename the all five hives by appending .old to the name.
  • Copy all the hives from the Regback folder, paste them in the Config folder, and then try to start the computer in Normal mode.

Drop your Comment