Fix Boot Manager Failed to Find OS Loader for Windows 7/8/10

September 3, 2018

How to quickly fix boot manager failed to find OS loader problem in Windows 7/8/8.1/10? Top 3 ways are provided in this article.

The Case

Yesterday, I am updating my Windows 7 Home Premium SP1 64-bit laptop with 3/4 latest optional update. After restarting, it opens Startup Repair and always opens every time I turn it on. And stating that the same error message:

Root cause found:

Boot manager failed to find Os Loader.

Repair action: File repair

Result: Failed. Error Code = 0x490

Time taken = 5522ms

Repair action: Boot configuration data store repair

Result: Failed. Error code = 0x490

Time taken = 156ms

Any help would be appreciated, Thanks a lot.

Start Repair Boot Manager Failed to Find OS Loader

Why Boot Manager failed to find OS loader in Windows 10/8/7?

This error message indicates that Startup Repair could not find the intact BOOTMGR bootloader at the location where it should be, which means boot loader is missing or corrupted. How to fix missing OS loader problem? Before that, you have the right to know why it occurs. Some reasons should be responsible for Windows startup repair Boot Manager failed to find OS loader problem:

  • Non-conventional power cut.

  • Your system hard disk might be damaged physically.

  • Bootloader was deleted.

  • System disk was removed.

How to fix boot manager failed to find OS loader in Windows 7/8/10?

Don’t be in panic if you trap in the boot manager failed to find OS loader error code 0x490, 0x2, or error code 0x3 this awkward circumstance. We will help you out with the 3 solutions. Refer to the following text:

Solution 1: Use System File Checker (Windows built-in tool, SFC)

System File Checker will check your Windows 7/8/10 installation for corrupted, invalid, or deleted system files. First of all, you must have a Windows installation disc.

Connect the Windows installation disc with your computer.

Restart your PC and boot it from the installation disc.

Select the language and keyboard options.

Choose Repair your computer -> Troubleshoot -> Advanced options -> Command Prompt.

Input the command to check system files errors:

sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows (where C: is the partition which holds your Windows 7/8/10 installation, or you could replace it with the right one.)

Solution 2: Repair bad sector or errors on system hard disk

If the system hard disk has bad sector or errors, the boot manager failed to find OS loader problem may occur. To check and repair bad sector or errors in system HDD, you could use the following commands to repair:

chkdsk C: /f /r (where C: is the system partition)

You must check all partitions on system hard disk to repair all bad sectors or errors. Just replace C: with the corresponding drive letter of each partition.

Solution 3: Repair MBR

You have two clues to repair MBR. One is Windows Installation disc; another is AOMEI Partition Assistant Standard. 

If you have a Windows installation disc, you could have it a try:

Connect the Windows installation disc with your computer.

Restart your PC and boot it from the installation disc.

Select the language and keyboard options, and other options.

Choose Repair your computer -> Troubleshoot -> Advanced options -> Command Prompt.

Enter the following commands:

bootrec.exe /fixmbr

bootrec.exe /fixboot

bootrec.exe /rebuildbcd

After completing the commands, check if the boot manager failed to find OS loader is solved. 

Or if you don’t have a Windows installation disc, you could use AOMEI Partition Assistant Standard to take a shoot:

1. Free download AOMEI Partition Assistant Standard edition, run it after installing. Connect a at least 16GB USB drive to a normal Windows computer which has the same operating system as yours.

2. At the main window of the software, choose Make Bootable Media under Wizards.

Make Bootable Media

3. Click Next and tick USB Boot Device to create bootable USB drive.

USB Boot Device

4. Press Proceed to create.

5. Boot your Windows 7/8/10 computer with unbootable issue from the bootable media, then AOMEI Partition Assistant Standard will show up on the desktop. Run this program.

6. Right click the system hard disk and choose Rebuild MBR.

Rebuild MBR

7. Select MBR type for your Windows OS.

MBR Type

8. Press Apply to commit the operation, then the boot manager failed to find OS loader should be fixed.

Apart from rebuild MBR, this freeware allows you to check and repair hard disk errors with Surface Test or Check Partition feature.

Conclusion

Besides, you might encounter BOOTMGR is missing, operating system not found, invalid system disk or other errors, you could use this freeware to fix. Besides, AOMEI Partition Assistant Standard has the ability to migrate OS to SSD, extend, split, resize, copy, wipe, move, format, delete partition, convert data between MBR and GPT without losing data, etc. For professional users, you could upgrade to Professional edition with more advanced functions to help you manage your hard disks or partitions. You can try Server edition if required.