Get the fix for the error Error loading operating system on Windows XP, Windows Vista and Windows 7.

About “Error loading operating system

The following information on this error has been compiled by NeoSmart Technologies, based on the information gathered and reported by our global network of engineers, developers, and technicians or partner organizations.

Description and Symptoms

The error messages, alerts, warnings, and symptoms below are tied to this error.

Symptom 1: “Error loading operating system” error screen on startup

This error shows when your computer’s BIOS doesn’t support the capacity of the hard disk where you are installing Windows XP or it’s not properly installed.

Issues with your hard disk drive’s partition can also be a major cause.

Alternative error messages. There are no other known alternative messages for this boot error, except the “Error loading operating system” text that appears on your computer’s black screen at startup.

Windows Error: Error loading operating system

The “Error loading operating system” error

Causes of this Error

This error has been known to occur as a result of one of the following causes:

Cause 1: The hard drive capacity is too big

The most common cause of this error is a hard drive that is too large to be supported by an outdated BIOS.

Cause 2: The hard drive partition is damaged

The hard drive’s partition may become damaged because of disk write errors, power outages or virus attacks. If that’s the case, the operating system cannot access the system files to boot properly and the loading process is halted.

Fix: Use Easy Recovery Essentials

Easy Recovery Essentials can fix many errors such as this automatically using its built-in Automated Repair option. EasyRE is currently available for Windows XP, Vista, 7 and 8 and can be downloaded and created on any PC.

  1. Download Easy Recovery Essentials. Make sure to note your Windows version (XP, Vista, 7 or 8) before you download EasyRE. This guide can help you identify what version of Windows you have installed.
  2. Burn the image. Follow these instructions on how to burn the bootable ISO image very carefully, as making a bootable CD can be tricky! Alternatively, these instructions explain how to create a bootable EasyRE recovery USB stick/drive.
  3. Boot up your PC from the Easy Recovery Essentials CD or USB you created.
  4. Once EasyRE is running, choose the “Automated Repair” option and click Continue.
    EasyRE Home

    Choose “Automated Repair” in Easy Recovery Essentials

  5. After EasyRE scans your computer’s drives, identify and select the drive letter for your Windows installation from the list, and then click on the Automated Repair button to begin.
    EasyRE displays a list of found Windows operating systems

    Choose the drive associated with the Windows installation you’re trying to repair.

  6. Easy Recovery Essentials will start analyzing the selected drive for problems. EasyRE will test for and attempt to automatically correct errors with the disk, partition, bootsector, filesystem, bootloader, and registry. No intervention is required, as EasyRE’s repair is fully automated:
    EasyRE: Automated Repair

    Easy Recovery Essentials searches for errors and makes corrections to the selected Windows installation.

  7. Once the process is complete, EasyRE will report its findings. Click on the Restart button to reboot your PC and test the changes.
  8. The “Error loading operating system” error should now be fixed as your PC begins to load:
    EasyRE: Automated Repair

    Windows, booting up successfully.

You can download Easy Recovery Essentials from here.

Fix Error loading operating system in Windows XP

You can fix this error without a Windows XP installation disc as you don’t need to boot into its Recovery Console.

Fix #1: Check your hard drive status in BIOS menu

Your computer may not see the hard drive correctly and can’t boot into XP. You can check its status in BIOS (or CMOS Setup), but the step to access it depends on your computer’s manufacturer.

Press one of these keys to enter BIOS/CMOS: DEL or F1 or F2 or ESC.

Fix #2: Recreate the partitions

If your hard disk is setup correctly, you can recreate the partitions by installing Windows XP again.

The “Error loading operating system” error is more likely to appear if your partitions were also changed by another system before installing XP, e.g. a Linux distribution.

When you reinstall Windows XP, make sure you delete all partitions and create the partitions you need to install XP.

Fix #3: Update the BIOS

If none of the above fixes works for you, you can try and update your computer’s BIOS. When starting up your computer check the messages at boot to determine your motherboard’s manufacturer.

Press Pause key at boot to pause the loading messages.

You can also check the BIOS version when accessing BIOS Menu/CMOS Setup. Go to Fix #1 above for the available keys to access it.

Fix Error loading operating system in Windows Vista

Windows Setup CD/DVD Required!
Some of the solutions below require the use of the Microsoft Windows setup CD or DVD. If your PC did not come with a Windows installation disc or if you no longer have your Windows setup media, you can use Easy Recovery Essentials for Windows instead. EasyRE will automatically find and fix many problems, and can also be used to solve this problem with the directions below.

You can also try the solutions from Windows 7.

Fix #1: Run System Restore from the disc

This solution works if you have System Restore enabled on your Windows Vista.

The steps for restoring your PC with System Restore:

  1. Insert the Windows Vista install disc
  2. Restart your computer and boot from the install disc
  3. Press a key when “Press any key to boot from CD or DVD” message appears on your screen
  4. Click on Repair your computer after selecting a language, time and keyboard method
  5. Select the drive where you installed Windows (usually C:\)
  6. ClickNext
  7. Select System Restore from the System Recovery Options window
  8. Follow the System Restore instructions to select a restore point
  9. Restore your PC by clicking Finish

Fix #2: Use Startup Repair

  1. Insert your Windows Vista install disc
  2. Restart your computer and boot from the CD
  3. Press any key when you see “Press any key to boot from CD or DVD”
  4. Click Repair your computer after selecting your language, time and keyboard method
  5. Select the drive of your Windows installation and click Next. The standard drive is usually C:\.
  6. Select Startup Repair and wait for the process to finish.

Fix Error loading operating system in Windows 7, Windows 8 and Windows 10

Windows Setup CD/DVD Required!
Some of the solutions below require the use of the Microsoft Windows setup CD or DVD. If your PC did not come with a Windows installation disc or if you no longer have your Windows setup media, you can use Easy Recovery Essentials for Windows instead. EasyRE will automatically find and fix many problems, and can also be used to solve this problem with the directions below.

Fix #1: Use bootrec.exe and rebuild the BCD

bootrec.exe is a tool built in the Windows Recovery Environment (Windows RE) that you can use to troubleshoot and repair the error. The steps for accessing bootrec.exe to rebuild the master boot sector:

  1. Insert your Windows 7 install disc
  2. Restart your computer and boot from the CD
  3. Press any key at the “Press any key to boot from CD or DVD” message
  4. Choose Repair your computer after you select the language, time and keyboard method
  5. Select your Windows installation drive (usually C:\)
  6. Click Next
  7. Select Command Prompt from System Recovery Options
  8. Type the following command and press Enter:
    bootrec /FixMbr
    bootrec /FixBoot
    bootrec /ScanOs
    bootrec /rebuildBcd
bootrec utility results screen

bootrec utility results screen

More Information

Linked Entries

Support Links

Applicable Systems

This Windows-related knowledgebase article applies to the following operating systems:

  • Windows XP (all editions)
  • Windows Vista (all editions)
  • Windows 7 (all editions)

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