The problem: Error loading operating system
“Hello, experts there! Recently, whenever I try to boot my Windows 10 computer, it says "Error loading operating system" on a black screen after the computer is powered on. I am worried about whether there is something wrong with my computer. What do you know about such problem? How can I fix it? Thanks for any suggestion!”
Most computer users might have met this irritating problem when starting Windows 7, Windows 8/8.1, Windows 10. It generally happens after the fresh installation of the OS, sudden power failure, system crash, or system restart.
The reasons: why Windows operating system not to load successfully?
As we all known, when a computer powers on and starts up, its BIOS and CMOS will check the system setup, hard drives, and then boot the operating system. If something goes wrong during the process, the operating system won’t be launched successfully.
So, besides the physical damage of hard drive, the following causes can also make your Windows not to load successfully:
The hard drive’s system partition is damaged.
Computer hard disk MBR information is not right.
The operating system’s files and folders are damaged.
The system BIOS does not support the hard drive.
Multiple hard drives have been connected to your computer, then the computer cannot detect which one is the the primary hard drive containing the operating system & system applications.
Some bad sectors on the system hard drive.
The solutions: how to fix it Windows 10/8/7?
No matter what makes your computer pop out “Error loading operating system” error, below are several methods through which you can fix this annoying issue with ease. NOTE: all the following methods operations are carried out in Windows 10 as an example.
Method 1. Rebuild the MBR directly (NOT Require Installation CD)
First of all, we would like to show how to fix “error loading operating system windows 10” without cd in case that most computer users don’t have an original installation disc. This method requires a free disk manager: AOMEI Partition Assistant, which allows you to create a bootable USB and then rebuild MBR directly without using the installation disc.
1. Connect an empty USB (over 8GB) to a working Windows 10 computer (since your Windows cannot boot). Then download the freeware.
2. Install and run AOMEI Partition Assistant. Click on the Make Bootable Media in the left pane. Follow the wizard to create a WinPE bootable USB disk. Disconnect the USB drive after it is done. (The bootable USB will contain installed AOMEI Partition Assistant.)
3. Plug the bootable USB into the computer with boot issue. Boot it from the USB by changing boot order in BIOS.
4. Once logged in, the AOMEI Partition Assistant Standard will load and start. In the main interface, right click the system disk and select “Rebuild MBR”.
5. In the pop-out mini window, choose the proper MBR type for Windows 10 and click “OK”.
6. Click “Apply->Proceed” in the main interface to commit the change.
This method could also apply to fix MBR for Windows 10/8/8.1/XP/Vista. If you meet such similar issue in Server like Windows Server 2012 boot BCD error, you can try AOMEI Partition Assistant Server Edition.
If you have the Windows installation disk in hand, you can try the following three methods.
Method 2. Perform Startup repair
Here is how to perform Startup Repair in Windows 10:
1. Insert your Windows 10 install disc into your computer and boot from it.
2. Choose the language and keyboard layout you prefer and click or tap “Next”
3. Click “Repair your computer” on the bottom left corner of the screen.
4. When asked what option you prefer, choose “Troubleshoot”.
5. On the “Advanced options” screen, click or tap “Startup Repair”.
Method 3. Run CHKDSK to check hard disk status
If you are unable to perform a startup repair, then your next option is to run CHKDSK to check whether the hard disk is in a healthy condition.
1. Insert the original Windows disc, restart your computer and boot from the disk.
2. At the Windows 10 Welcome screen, click "Repair your computer-> Troubleshoot->Advanced Options->Command Prompt".
3. When the Command Prompt window appears, type the command: chkdsk c: /f /r /x and press Enter. (c represents the drive where Windows operating system is installed)
Or you can run AOMEI Partition Assistant under WinPE mode like you do in method 1 and make a disk surface test to make whether there are some bad sectors on the system disk.
Method 4. Restore the MBR information of hard disk
First open a Command Prompt window like you do in the method 2, and then in the window, input the following commands and press Enter after each to fix MBR in Windows 10.
Then, exit Command Prompt and restart your computer.
So do not feel depressing any more when you encounter the “Error loading operating system” in Windows 10/8/7. Refer to this article to find the actual reasons behind this issue and try the solutions above to remove this boot failure issue with ease.