Windows Won't Boot, Pro Tip Fix Corrupt MBR Bootloader Of HDDSSD

Your computer’s boot process is like a sophisticated digital dance, and the Bootloader serves as the maestro, orchestrating the symphony of system initiation. However, in the vast world of binary operations, this virtuoso can stumble, giving in to the unseen forces of corruption.understanding the topic

When the cosmic harmony of your machine is disrupted, a silent struggle ensues within your storage, creating a scenario where the Bootloader, meant to be the gateway to your digital realm, falters in its performance.

Imagine this: a cryptic encounter with a Blue Screen Error, a digital sonnet interrupted by the unsettling refrain of “Operating System not found.” In the sacred chambers of your device, the harmony is shattered, and the melody of your digital existence is silenced. This is the moment when the delicate threads holding your system together start to unravel, resulting in a screen painted with numerous errors.

The cryptic language of the digital realm reveals itself in messages like “Invalid partition table” and the ominous proclamation of “No bootable medium found.” These seemingly innocuous phrases carry the weight of a cosmic dilemma—a corrupted MBR or UEFI GPT Bootloader System Volume, a complex puzzle that requires the touch of a virtuoso to untangle.

In our ensuing exploration, we embark on a quest to decipher the binary runes, navigate the intricate pathways of system bootloader volumes, and unveil the arcane methods of remedying a system ensnared in the clutches of corruption.

Exploring The MBR & GPT Bootloader: What It Really Is?

Let’s talk bootloaders—those little powerhouses tucked away in the boot sector of your trusty Hard Disk Drive (HDD) or Solid State Drive (SSD). Picture this: your computer is gearing up for action, and the first player to hit the stage is the BIOS or UEFI. Now, our superhero, the bootloader, steps into the spotlight.

For the MBR crowd (that’s Master Boot Record, for the uninitiated), the bootloader dives into the MBR, hunting for the lowdown on partitions. It sniffs out the active partition, grabs its boot sector, and voila—we’re in business. But hold up, MBR has its quirks: it maxes out at 2.2 terabytes and only lets you juggle four primary partitions. Talk about limitations!

On the flip side, enter GPT (that’s GUID Partition Table, in case you’re wondering). This modern maverick flaunts a GUID partition table, flexing its muscles with support for storage capacities beyond 2.2 TB and a party-friendly guest list of up to 128 partitions. The GPT bootloader and UEFI? They’re like BFFs with benefits, bringing secure boot and lightning-fast startup times to the tech party.

To sum it up: bootloaders are the VIPs of computer startup, MBR and GPT dictate how your storage space gets divided up, and in the world of BIOS and UEFI firmware. It’s pivotal to grasp the distinction between MBR and GPT when delving into bootloader troubles. Why? Well, the steps you take to diagnose and fix issues depend on the nitty-gritty details of the partitioning scheme at hand. Customizing your approach is the name of the game here.

Why Does The MBR or UEFI GPT System Volume Get Corrupted?

Despite its crucial role in kickstarting the computer, the Bootloader System volume isn’t immune to corruption, and when it happens, it can throw a real wrench into your computer’s functionality. To grasp why the MBR or GPT goes wonky, let’s take a deep dive into the digital realms of vulnerabilities and operational intricacies.

  • Malware and Viruses: sneaky malware slipping into your system and setting its sights on the MBR or GPT. It can tweak or downright overwrite it, causing chaos during the boot-up routine.
  • Hardware Issues: Now, real-world problems like power outages, sudden shutdowns, or wonky hardware components can play havoc with the MBR or GPT’s read/write processes. The result? Data inconsistencies or, worst case, data loss.
  • Human Errors: Even the best of us slip up. Accidentally deleting or formatting the MBR during maintenance or partition juggling, or attempting to play System Volume Magician without knowing the tricks, can lead to corruption.
  • Software Conflicts: Installing or uninstalling certain applications, especially the ones that go deep into the system, might unknowingly tango with the system volume, giving it a one-way ticket to corruption.
  • System Operations: Sometimes, the routine stuff can cause chaos too. Incompatibilities or conflicts during regular system operations might throw the MBR or GPT off its game.

Mitigating this risk isn’t rocket science. Tighten up your security, keep your hardware in check, and handle your system with care. Doing so ensures your MBR or GPT stays in tip-top shape, keeping your computer running smoothly.

Let’s See How To Fix The MBR Or UEFI GPT System Volume

Addressing MBR or UEFI GPT issues now provides users with two distinct paths: a user-friendly route through the Startup Repair tool and a more advanced but powerful method utilizing Command Prompt (CMD) for manual bootloader restoration. These options cater to different user preferences and technical expertise levels, offering flexibility in dealing with System Volume-related complications.

#1 Easy Way: Startup Repair

The easy way to address the MBR or GPT issues is through the user-friendly Startup Repair tool. This accessible solution is designed for individuals who prefer a streamlined and automated approach to fixing common startup problems.

After a series of failed startup attempts, Windows detects the issue and automatically triggers the appearance of the Windows Recovery Environment (WinRE). This environment serves as the backdrop for the Startup Repair tool, seamlessly transitioning into the troubleshooting process.

On the other hand, users can proactively access Startup Repair by utilizing the Windows Installation Media. Inserting a Windows Installation USB or DVD (make sure to use the same OS version iso and just don’t try fixing Windows 11 with Windows 10 Setup) and booting from it opens up the installation setup page. Selecting the “Repair your computer” option initiates the Windows Recovery Environment, where the Startup Repair tool can be engaged.

The charm of Startup Repair lies in its simplicity. Users are guided through a step-by-step process, and the tool automates the diagnosis and resolution of common MBR or GPT-related issues. This approach caters to individuals who may not be well-versed in command-line operations or prefer a streamlined solution.

#2 Hard Way: CMD and Manual Bootloader Restoration

When embarking on the journey of manual bootloader restoration using the Command Prompt, the first step involves gaining access to CMD itself. While there are various methods to open CMD, the most efficient and recommended way is through the Windows Recovery Environment (WinRE).

Just try those steps as I suggest above to open the WinRE, and if using Windows Setup, then make sure to use the same OS version iso for the Windows Installation Media creation.

Open CMD Using Shift + F10 Key Combo on Windows Installation Setup

Moving Forward, Let’s Insert Some Commands in CMD:

Before diving into the nuances of restoring either the MBR or UEFI bootloader, the first order of business is to determine whether your system is rocking the MBR Bootloader or its UEFI GPT (Unified Extensible Firmware Interface – GUID Partition Table) counterpart. These two bootloaders march to their own beats, requiring specific setups. Consequently, the steps to address issues with each one differ a tad.

To discern the bootloader type your system employs, follow these steps:

  1. Open Diskpart: Begin by typing “diskpart” in the Command Prompt and pressing Enter. This command opens the Diskpart utility, a tool used for disk management tasks.
  2. List Disks: Enter the command “list disk” in Diskpart and press Enter. This command provides an overview of the disks connected to your system, including details about their partitions and configurations.

Now, it’s time to identify whether your computer is using the MBR Bootloader:

  • Inspect the GPT Block Section:
    • If your system operates on the MBR Bootloader, navigate to the GPT (GUID Partition Table) block section of your disk. This area needs to be blank.
    • Otherwise, the presence of a white star on the GPT Block indicates that the disk is configured with the UEFI GPT Bootloader.Checking MBR Bootloader

After you’ve smoothly landed in the Command Prompt (CMD) on your computer, the following move is to tackle and iron out any issues lurking in the system volume. Keep in mind that, for the most part, the steps in this fix-up dance stay the same, covering routine tasks like Steps 1, 2, and 4. But here’s the kicker: when you waltz into Step 3, pay extra attention. This is where you dish out bootloader-specific moves, finely tuned to match the rhythm of your system.

Step 1: Identifying “Windows” and “System Reserve” Drives

In this crucial first step of the troubleshooting process, the goal is to pinpoint the drive letters associated with the “Windows” and “System Reserve” partitions. Follow the outlined steps in Command Prompt to gather the necessary information:

  1. List Volumes:
    • Begin by typing “diskpart” in CMD and pressing Enter to access the Diskpart utility.command 1
    • Execute the command “list vol” to display a comprehensive list of all volumes on your PC. This provides an overview of each drive’s attributes.command 2
  2. Note Down Volume Letters:
    • Take note of all the volume letters displayed during the “list vol” command. These letters are crucial for later identification of the “Windows” and “System Reserve” drives.
    • Exit Diskpart using the “exit” command after noting down the relevant information.command 3
  3. Explore Drive Directories:
    • Now, systematically navigate through each drive’s directory to identify the required files.
    • Use the command format “drive letter:” (e.g., “c:“) to switch to the desired drive and press Enter.
    • Execute “dir /a” to reveal all files in the drive, unveiling critical information about its content.command 4
  4. Identifying “System Reserve” Drive:
    • The “System Reserve” drive is typically characterized by a small volume size, often around 50 to 100 MB or occasionally 500 MB. This drive harbors essential bootloader files such as “bootmgr” or “boot”.
    • Examine the content of each drive to identify the one containing these bootloader files.command 5
  5. Verifying “Windows” Drive:
    • To confirm the “Windows” drive, inspect the directories for the presence of a folder named “Windows”. This folder signifies the main operating system drive of the computer.command 6

Step 2: Format “System Reserve” Drives

Following the identification of the “System Reserve” drive in the previous step, the next crucial phase involves formatting this drive to eliminate any remnants of corrupted bootloader files. This step is vital in preparing the ground for a clean and effective restoration of the MBR or GPT. Here’s a detailed guide on how to format the “System Reserve” drive:

  1. Access Diskpart: Launch Diskpart by entering the “diskpart” command in Command Prompt (CMD) and pressing Enter. This opens the Diskpart utility, providing advanced disk management functionalities.command 7
  2. List Volumes to Find “System Reserve” Drive: Execute the “list vol” command within Diskpart to retrieve a list of volumes on your system. This will help identify the volume number associated with the “System Reserve” drive.command 8
  3. Select the “System Reserve” Drive: Utilize the “select vol {System Reserve Disk Vol No.}” command, replacing “{System Reserve Disk Vol No.}” with the actual volume number of the “System Reserve” drive. For instance, if the volume number is 2, the command will be “select vol 2”.
  4. Format the Drive: Execute the command “format fs=ntfs quick” to initiate the formatting process. This command swiftly formats the “System Reserve” drive with the NTFS file system, ensuring a quick and efficient cleanup of the drive. Make sure to exit after formatting using the “exit” command.command 9

Step 3: Recreating and Fixing the MBR or UEFI GPT Bootloader

Having successfully formatted the “System Reserve” drive, the next crucial phase involves recreating and fixing the MBR or GPT bootloader to restore the system’s boot functionality. Follow the outlined commands meticulously to ensure a smooth and effective recovery process:

  1. Recreating MBR Bootloader Files (Use this command if your Windows is configured with MBR with old BIOS): Type the command: “bcdboot {path to windows folder} /s {path to System Reserve drive}”. Replace “{path to windows folder}” with the actual path to the “Windows” folder, and “{path to System Reserve drive}” with the drive letter of the formatted “System Reserve” drive. For example, “bcdboot d:\windows /s c:” recreates the bootloader files. Pay attention to the correct paths in the “bcdboot” command, ensuring accuracy in specifying the location of the “Windows” folder and the “System Reserve” drive.command 10
  2. Recreating UEFI GPT Bootloader Files (Use this command if your Windows is configured with GPT with new UEFI): Type the command: “bcdboot {path to windows folder} /s {path to System Reserve drive} /f UEFI”. Replace “{path to windows folder}” with the actual path to the “Windows” folder, and “{path to System Reserve drive}” with the drive letter of the formatted “System Reserve” drive. For example, “bcdboot d:\windows /s c: /f UEFI” recreates the bootloader files. Pay attention to the correct paths in the “bcdboot” command, ensuring accuracy in specifying the location of the “Windows” folder and the “System Reserve” drive. command 10.2
  3. Reconfiguring the MBR: Execute the command “bootrec /fixmbr” to reconfigure the bootmgr file, ensuring a clean and functional MBR.
  4. Reconfiguring Boot Files: Execute the command “bootrec /fixboot” to reconfigure the boot files. If an “access is denied” error occurs, type: “bootsect /nt60 sys” and then re-enter the “bootrec /fixboot” command.fixing access denied error on fixboot command
  5. Rebuilding the BCD (Boot Configuration Data): Execute the command “bootrec /rebuildbcd” to rebuild the BCD, which is a crucial step in ensuring the correct identification of Windows installations. In case, CMD indicates “Total identified windows installation: 0”, do not worry, as this issue will be resolved in the subsequent step.command 11

By systematically executing these commands, you recreate and reconfigure the entire MBR or GPT bootloader. The “bcdboot” command ensures that the necessary bootloader files are placed in the “System Reserve” drive, providing the foundation for a successful boot process.

Step 4: Finally Reactivating System Reserve MBR Bootloader Drive

In the conclusive step of this comprehensive recovery process, we focus on reactivating the “System Reserve” MBR or GPT bootloader drive. This finalization ensures that the bootloader is active and ready to facilitate the seamless startup of your Windows system. Follow these steps diligently to complete the restoration:

  1. Accessing Diskpart: Open Diskpart by entering the “diskpart” command in Command Prompt (CMD) and pressing Enter. This launches the Diskpart utility, a tool for disk management tasks.
  2. Listing Volumes: Execute the “list vol” command within Diskpart to display a list of volumes on your system. This will help identify the volume number associated with the “System Reserve” drive.
  3. Selecting the “System Reserve” Drive: Use the “select vol {Volume number of System reserve drive}” command, replacing “{Volume number of System reserve drive}” with the actual volume number of the “System Reserve” drive. For example, if the volume number is 2, the command will be “select vol 2”.
  4. Activating the Drive: Type the command “active” to activate the selected volume. This step designates the “System Reserve” drive as the active partition, ensuring that it plays a pivotal role in the system’s boot process.
  5. Exiting Diskpart: Exit Diskpart by typing “exit” and pressing Enter. This concludes the interaction with Diskpart, having successfully activated the “System Reserve” drive.command 12
  6. Restarting Your Computer: Restart your computer to witness the final result of the successful restoration process. The reactivation of the “System Reserve” MBR or GPT bootloader drive sets the stage for a smooth and functional Windows startup.

By adhering to these steps with utmost precision, you guarantee the meticulous reinstatement of the fundamental components within the Master Boot Record. The result? The bootloader struts back into action, orchestrating the boot process with finesse. The grand finale of this procedure manifests in the triumphant resurrection of your Windows operating system, signaling the triumphant resolution of MBR or GPT-related hiccups and the complete restoration of your computer’s operational integrity. Curtain up on a flawlessly operational system!

Also, ensuring the well-being of your MBR or GPT takes a critical turn with the implementation of a top-notch antivirus solution. Although Windows Defender and some free antivirus tools toss in a basic safety net, they might not always cut it when facing the intricate dance of ever-evolving malware. Enter the stage, professional-grade antivirus programs. These stalwarts, celebrated for their knack for advanced threat detection, hoist the bar higher, delivering a more fortified defense against the myriad of cyber threats. It’s like having a cybersecurity superhero on duty for your MBR’s protection!

AVAST Antivirus


Suggested Articles:





41 COMMENTS

  1. When I try use ( D: ) it say: Data error
    and D: is written on Raw not Ntfs, how can I change it???
    tried with CHKDSK D: /F but didnt work (Failed to transfer logged messages to the event log with ststus 50)

  2. I’m at Leaving Disk part but it doesn’t say sources. Its X:\Windows\System32>
    And its just blinking still. I tried entering my drive but said device not ready… not sure what to do. Also it says the 2 partitions RAW and recovery NTFS are healthy but the removable and the DVD ROM No Media with 0 B. I haven’t lost any data have I ? Only some files n photos were backed up. I’ve always been able to reset an recover but I’ve never had unmountable error msg before.

  3. All of these steps didnt work for me so i assumed that i need a fresh installation of windows 7 once again, however whenever i try to insert the installation disk and start the setup my system always hang up on “setup is starting” so is there a way to fix this issue so i can install Windows once again,as i think its because of the unmountable drive error.

  4. Hi, my first symptom of Win10 1709 build 16299.125 is that the Windows apps stop working, like Start, Calculator, etc. They are fine again after restart, then after a while, they stop working again. Then, in the evening, I turn off the computer, the next morning Windows will not boot. I boot from USB Windows Media Creation Tool, but Repair, Restore, etc. all fail. CMD starts, but when I get to bootrec /fixboot, I receive the message “fixboot access denied” only fixmbr succeeds as well as rebuildbcd. Luckily, Windows booted again. I reinstalled Windows as Upgrade, so I can keep my programs and settings but I still fear that this problem will reappear after some time again.

  5. Hi Madhur,
    I am attempting this on a Lenovo Ideapad Y550 and am unable to even start in Safemade, with a BSOD. While trying to load safe mode when it says “Please Wait…” and goes through a bunch of files, it gets hung up on windows\system32\drivers\disk.sys, then crashes.
    I don’t have the repair CD, and can’t get to a Command Prompt. Is the only option to remove the hard drive and replace with a new one with OS already installed?

Leave a Reply to FeniksXD Cancel reply

Please enter your comment!
Please enter your name here