By Ivy / Last update March 4, 2020

About Error Loading Operating System

The error message “Error Loading Operating System” with a black screen often appears while starting your computer, owing to a fresh installation of Windows operating system, sudden power failure, system crash, system restart, viruses attack, disk not properly partitioned.

As normal, when you boot your computer, the BIOS and CMOS will check the operating system and hardware and then boot your computer. But if there is any issue, your computer will fail to boot.

Reasons to Error Loading Operating System

Every error has its own cause, black screen error loading operating system windows 7 is not an exception. Here, I will list some reasons in the following.

  • The system BIOS does not support the hard drive. You need to update BIOS from the manufacturer’s website.

  • The hard drive is not properly set up in CMOS.

  • The computer has wrong MBR information. You are supposed to restore the MBR information of the disk.

  • The system file is damaged.

  • The system partition is damaged due to sudden power cuts, virus infection.

  • The disk is corrupted completely. You need a new one.

  • The disk containing operating system cannot be detected owing to multiple disks connected.

How to fix error loading operating system in Windows 7?

After you receive error loading operating system in Windows 7, you cannot enter your computer. In this case, you can create a recovery disk or just use the installation disk provided by manufacturer. You may use it in the following.

All solutions below are applied to error loading operating system on Dell/ASUS/HP/Acer/Lenovo, thus you can refer to the following way and see if it works.

Updating BIOS of your computer

Step 1. Check out the motherboard in user manual of your mainboard.

Step 2. Identify the current BIOS version from System Information.

Step 3. Download the latest BIOS update via laptop manufacturer's website.

Step 4. Run the BIOS update and Restart your computer to apply the change.

Step 5. Go to CMOS setup and make sure the disk is detected. Then, change the Access mode to Large or MBA. It supports for large capacity of hard drive.

Restore MBR information of the disk

Wrong MBR information can be a cause for this error. You can use bootrec.exe to restore it to a correct state.

The first thing is to get command prompt window. You can use insert Windows installation disc into your computer and restart your computer from it, then click Repair your computer > Troubleshoot > Advanced Options > Command Prompt in order.

Repair Your Computer

Step 1. After command prompt windows loading, type the following commands and hit Enter.

  • bootrec /FixMbr

  • bootrec /FixBoot

  • bootrec /ScanOs

  • bootrec /RebuildBcd

Restore the MBR Information of Disk

Step 2. Remove installation disc first, and then type exit and press Enter.

Step 3. Restart your computer. If your computer boot as normal, no further steps are needed.

Using CHKDSK command prompt

The CHKDSK command can fix the corrupted system files on your computer. Just try it.

Step 1. Get to the command prompt window.

Step 2. Type chkdsk C:/r and hit Enter to run the pending operation. If this partition is in use, you will be asked to run this operation in the next system restart. Type Y and press Enter.


Step 3. Restart your computer.

Using Startup Repair tool

Startup repair can fix many startup problems. If the problems still exist, you should try startup repair using installation disc.

Step 1. Insert Windows installation disc into your computer.

Step 2. Restart your computer from this disc and click Repair your computer > Troubleshoot > Advanced Options > Startup Repair.

Startup Repair Advanced Options

Step 3. Just wait and restart your computer after the operation finish.

Writing zeros to hard drive

If there are no effective way that can solve your issue, you can try to write zeros to hard drive. In a simple word, you need to format the disk.

Step 1. Go to command prompt windows.

Step 2. Type format F: /fs:ntfs /p:1 and hit enter to format this partition and write zero to every sector of disk. If it asks you to enter volume label, type the label and hit enter.

Step 3. Click Y to confirm that you want to format this partition. Restart your computer after the process ends.

Write Zeros to Hard Drive

How to avoid data loss owing to startup issues?

If you do not lose any data on your computer, you will never know the importance of backup. It can save your computer and files in most cases.

Now, start to get aware of backup and restore software and create a backup for your computer.

For backup and restore software, I recommend you free AOMEI Backupper. It's very easy to use, even for beginner. It allows you to create a file backup, partition backup, disk backup and partition backup. And it adds more useful features for these backup. You can create a schedule backup for almost all backups. Besides, you still can manage disk space via deleting old backups.

Detailed steps are below.

Step 1. Download free AOMEI Backupper, install and launch it.

Step 2. Click Backup and System Backup subsequently. Also, you can click File Backup, Partition Backup, Disk Backup.

System Backup

Step 3. Modify Task Name and click where the arrow point and select a location for your backup.

Select Destination

Step 4. Set up Backup Options, Schedule and Scheme according to your needs. Then, click Start Backup.



1. For Backup Options, there are two important features, including Compression and Encryption. Compression can save your disk space. Encryption can ensure the security of your backup.

2. For Backup Schedule, it can help you backup at a regular time, such as, daily, weekly, monthly, event-trigger.

>>Besides, a new feature called USB plug in has been added to Schedule. Once you use a USB to create a backup, AOMEI Backupper will automatically start to backup to USB when plugged in your computer. It’s interesting. You can download the free trial version, try USB plug in feature first and then decide if you want to upgrade.

>>To save your disk space, you can use differential backup or incremental backup instead of full backup.

3. Backup scheme is designed to manage disk space and delete old backups with a special rule.