How to Fix An Operating System Wasn't Found Error Message
When powering on the computer, you may receive below error message:
There are few reasons why you may receive above error message, please follow below resolution steps.
A bootable USB or DVD with Windows Vista or higher is needed to bring up the Command Prompt. If you don’t have a bootable Windows ISO image available, you can obtain one from here.
Below tutorials can be followed to create bootable Windows USB flash drive or Rufus utility can be use to create bootable Windows USB flash drive.
How to Create a Bootable Windows Vista or Windows 7 USB Flash Drive
How to Create a Bootable Windows 8, Windows 8.1 or Windows 10 USB Flash Drive
Boot Computer into Windows Recovery Environment (WinRE) With Windows Installation DVD
1. Insert the Windows Setup DVD into your DVD drive.
2. Configured the BIOS boot device order setting to start from a CD/DVD optical drive.
3. If prompted, press any key to start the computer from the Windows Setup DVD.
4. Choose your language settings, and then click Next button.
5. Click “Repair your computer”.
6 . To access WinRE environment from Windows Vista and Windows 7 select the Windows installation you want to repair, and then click Next button.
After you have click the Next button, the System Recovery Options menu appears.
7. To access WinRE from Windows 8, 8.1 and Windows 10, click “Troubleshoot” option.
After you click Troubleshoot the Troubleshoot screen appears.
8. Click “Advanced options” on the Troubleshoot screen to access more WinRE recovery utility’s in “Advanced options” screen.
The Advanced Options screen except for “Windows Memory Diagnostics” utility have same recovery utility’s as the previous versions of Windows OS WinRE environment.
Step 1:
If Automatic Repair (Startup Repair) tool fails to resolve the issue try System Restore tool to restore Windows OS to a previous state that was without any system errors. If the error not resolved then try next steps suggestions.
Step 2:
You will have to use Diskpart command line tool to assign a drive letter for System Reserved partition. You will use the bcdboot command line tool to recreate the System Reserved partition boot files.
The output of the below commands may display the name of the System Reserved partition as a System, ESP or EFI System Partition.
1. Type diskpart and press Enter.
2. Type list volume and press Enter.
3. Under the label row, find the label System Reserved and note its corresponding Volume number.
4. Now type select Volume=N and press Enter, where N is the Volume number you noted earlier.
5. Now type assign letter=w and press Enter.
6. Type exit and press Enter.
7. Type bcdboot C:\Windows /s w: /f ALL and press Enter.
Please replace partition letter C: with Windows installed partition letter.
When computer boots into WinRE environment the drive letter assign to Windows partition may not be C: drive letter because Windows 7, 8 , 8.1 and 10 creates a separate system partition when it's installed from scratch. The system partition contains boot files WinRE assigns the system partition the C: drive letter and the Windows installed partition will be assign any other drive letter usually D: drive letter is assign to Windows installed partition. The Bcdedit /enum | find "osdevice" command can be use to find out the drive letter of the Windows installed partition the output of the Bcdedit command is similar to this osdevice partition=D:. The drive letter after partition= is the drive letter of the Windows partition.
8. Restart your computer.
Step 3:
The C: partition may not be mark as active system partition. You will need to mark C: partition as active partition from Command Prompt using Diskpart command line tool.
1. Open the Command Prompt.
2. Type Diskpart, press Enter key.
3. Type List Disk, press Enter key.
Take note of the Disk number of where Windows installed partition is located.
4. Type Select Disk 0, press Enter key.
Replace the disk number zero (0) with disk number assign to Windows installed disk number.
5. Type List Volumes, press Enter key.
Take note of the C: volume number.
6. Type Select Volume 0, press Enter key.
Replace volume number zero (0) with volume number assign to C: partition.
7. Type Active, press Enter key.
8. Restart your computer.
Step 4:
If marking C: partition active wont resolve the issue then BCD store could be damage and need to be repaired.
The master boot record (MBR) and or boot sector could be damage as well, execute below commands.
1. Open the Command Prompt
2. Type Bootrec /FixMBR, press Enter key.
3. Type Bootrec /FixBoot, press Enter key.
4. Type Bootrec /RebuildBcd, press Enter key.
5. Restart your computer.
Hopefully one of these troubleshooting steps will resolve the "An operating system wasn’t found" error.
Did you find this tutorial helpful? Don’t forget to share your views with us.
There are few reasons why you may receive above error message, please follow below resolution steps.
A bootable USB or DVD with Windows Vista or higher is needed to bring up the Command Prompt. If you don’t have a bootable Windows ISO image available, you can obtain one from here.
Below tutorials can be followed to create bootable Windows USB flash drive or Rufus utility can be use to create bootable Windows USB flash drive.
How to Create a Bootable Windows Vista or Windows 7 USB Flash Drive
How to Create a Bootable Windows 8, Windows 8.1 or Windows 10 USB Flash Drive
Boot Computer into Windows Recovery Environment (WinRE) With Windows Installation DVD
1. Insert the Windows Setup DVD into your DVD drive.
2. Configured the BIOS boot device order setting to start from a CD/DVD optical drive.
3. If prompted, press any key to start the computer from the Windows Setup DVD.
4. Choose your language settings, and then click Next button.
5. Click “Repair your computer”.
6 . To access WinRE environment from Windows Vista and Windows 7 select the Windows installation you want to repair, and then click Next button.
After you have click the Next button, the System Recovery Options menu appears.
7. To access WinRE from Windows 8, 8.1 and Windows 10, click “Troubleshoot” option.
After you click Troubleshoot the Troubleshoot screen appears.
8. Click “Advanced options” on the Troubleshoot screen to access more WinRE recovery utility’s in “Advanced options” screen.
The Advanced Options screen except for “Windows Memory Diagnostics” utility have same recovery utility’s as the previous versions of Windows OS WinRE environment.
Step 1:
If Automatic Repair (Startup Repair) tool fails to resolve the issue try System Restore tool to restore Windows OS to a previous state that was without any system errors. If the error not resolved then try next steps suggestions.
Step 2:
You will have to use Diskpart command line tool to assign a drive letter for System Reserved partition. You will use the bcdboot command line tool to recreate the System Reserved partition boot files.
The output of the below commands may display the name of the System Reserved partition as a System, ESP or EFI System Partition.
1. Type diskpart and press Enter.
2. Type list volume and press Enter.
3. Under the label row, find the label System Reserved and note its corresponding Volume number.
4. Now type select Volume=N and press Enter, where N is the Volume number you noted earlier.
5. Now type assign letter=w and press Enter.
6. Type exit and press Enter.
7. Type bcdboot C:\Windows /s w: /f ALL and press Enter.
Please replace partition letter C: with Windows installed partition letter.
When computer boots into WinRE environment the drive letter assign to Windows partition may not be C: drive letter because Windows 7, 8 , 8.1 and 10 creates a separate system partition when it's installed from scratch. The system partition contains boot files WinRE assigns the system partition the C: drive letter and the Windows installed partition will be assign any other drive letter usually D: drive letter is assign to Windows installed partition. The Bcdedit /enum | find "osdevice" command can be use to find out the drive letter of the Windows installed partition the output of the Bcdedit command is similar to this osdevice partition=D:. The drive letter after partition= is the drive letter of the Windows partition.
8. Restart your computer.
Step 3:
The C: partition may not be mark as active system partition. You will need to mark C: partition as active partition from Command Prompt using Diskpart command line tool.
Information
GPT disk doesn't need any active partition only MBR disk needs one active partition
1. Open the Command Prompt.
2. Type Diskpart, press Enter key.
3. Type List Disk, press Enter key.
Take note of the Disk number of where Windows installed partition is located.
4. Type Select Disk 0, press Enter key.
Replace the disk number zero (0) with disk number assign to Windows installed disk number.
5. Type List Volumes, press Enter key.
Take note of the C: volume number.
6. Type Select Volume 0, press Enter key.
Replace volume number zero (0) with volume number assign to C: partition.
7. Type Active, press Enter key.
8. Restart your computer.
Step 4:
If marking C: partition active wont resolve the issue then BCD store could be damage and need to be repaired.
The master boot record (MBR) and or boot sector could be damage as well, execute below commands.
1. Open the Command Prompt
2. Type Bootrec /FixMBR, press Enter key.
3. Type Bootrec /FixBoot, press Enter key.
4. Type Bootrec /RebuildBcd, press Enter key.
5. Restart your computer.
Hopefully one of these troubleshooting steps will resolve the "An operating system wasn’t found" error.
Did you find this tutorial helpful? Don’t forget to share your views with us.