9 Ways to Fix Non System Disk or Disk Error on Laptops/PC

Summary

How do you fix a non-system disk or disk error on HP, Dell, Compaq, Acer, Lenovo PCs or laptops? Besides some basic troubleshooting methods, this page focuses on how to use third-party bootable media data recovery software and bootable media partition manager software to solve the non-system disk or disk error without losing data.

About non-system disk or disk error

"What does it mean when your computer says non-system disk or disk error? It's an HP Compaq 6000 that runs trouble when I start it, a message comes up displaying as Non-system disk error or disks error, replace and strike any key when ready."

For your information, the non-system disk or disk error message might appear when the computer BIOS cannot find a bootable operating system on any of the storage devices included in its boot path, or it fails to locate the boot disk. Similar error messages include boot device not found, operating system not found or missing operating system...

General troubleshooting for non-system disk or disk error

According to HP's help page, a very detailed guide is offered for HP notebook PCs to work out the "Non-system disk error" as well as "disk error" that appears on a black screen in Windows 10, 7 and Vista. In fact, the given suggestions are also applicable to other desktops and laptops, such as Dell, Compaq, Acer, Lenovo, etc.

In conclusion, you can try at first the four basic approaches, which usually helps fix the setup and stop error during Windows installation or startup.

Fix 1. Remove all the non-bootable storage devices

What storage drives are currently connected to your computer? Check and try to remove all the non-bootable storage devices, namely non-system drives, that make the computer have trouble to boot from, including a floppy disk or CD/DVD disc. After the safe ejection, try to turn off and on the computer and see if the error persists on.

Fix 2. Check on your HDD's IDE or SATA cable

Check on your HDD's IDE or SATA cable and make sure that the cable connecting the HDD to the motherboard is fastened securely and restart your computer.

Fix 3. Set the right boot priority in BIOS/UEFI

Access to your computer's BIOS/UEFI environment and make sure that the hard disk drive you're trying to boot from is in the right boot order settings, which should be at the very top of the boot order list. To change the boot order, you can do it like this:

• Press the key required to enter the BIOS or UEFI setup screen (Usually Esc, F2, F8, F10) while computer restarting.
• In BIOS, use the arrow keys on the keyboard to select the Boot tab and give the system drive the boot priority, which should be placed on the top.
• In UEFI, you can use the mouse pointer to specify the boot sequence.
• Save and exit the BIOS/UEFI setup utility. The computer will restart with the changed settings.

Fix 4. Remove and reinstall the hard drive

A bad connection between the hard drive and the computer would also expose such unbootable issues, and most of the time it's because the hard drive was once dropped or jarred. To fix the connection problem, you must do it in a safe way by following the standard process offered here.

• Cut off the power
• Take out the battery (For laptops only)
• Remove the system disk (HDD or SSD)
• Reinstall the system disk
• Reinstall the battery (For laptops only)
• Power on the computer

Advanced troubleshooting for non-system disk or disk error

Excluding the outside factors that caused the non-system disk or disk error, you have to accept the facts that something went wrong with the hard disk drive's boot files, which might become damaged or corrupted, and usually repairing the HDD's boot sector, master boot record (MBR) and boot configuration data (BCD) should take effect.

What's more, to protect data on a non-bootable computer, you're strongly suggested to take the right steps to fix the issue wisely.

First of all, download EaseUS bootable media data recovery software to access and recover hard drive data without OS.

Later, download EaseUS bootable partition manager to rebuild MBR.

Fix 5. Access hard drive and recover data from the hard disk without OS

1. Create a WinPE Bootable Disk

First, download and install EaseUS Data Recovery Wizard WinPE Edition on a working computer. Then, create a WinPE bootable disk of EaseUS data recovery software, which will help you access your hard drive data without booting into Windows.

Step 1. Launch EaseUS bootable data recovery software on a working computer.

Step 2. Select CD/DVD or USB drive and click "Proceed" to create a bootable disk. 

2. Recover data from crashed OS

Connect the WinPE bootable disk you have made to the PC with the corrupted Windows system, then, restart the computer and go to BIOS to change the boot sequence. Press F2 when you start your PC. It will allow you to run EaseUS data recovery software and recover data without Windows.

Step 1. Select the disk where you want to recover data and click the "Scan" button.

Step 2. Let the software scan the selected disk to find all the files and folders.

Step 3. Preview and choose the files you want. Click the "Recover" button to save them to a safe place. You'd better choose a different drive to avoid data overwriting.

Fix 6. Fix non-system disk or disk error by rebuilding MBR

Download and install EaseUS Partition Master Professional on a normal computer.

Step 1. Create a WinPE bootable disk.

• Download and launch EaseUS Partition Master on a new PC which runs the same system as yours.
• Click "WinPE Creator" on the toolbar. And select to create the bootable disk on a USB drive. If your computer has a CD/DVD drive, you can also create the bootable disk to CD/DVD.
• Click "Proceed" to finish the process.

Step 2. Rebuild MBR.

• Connect the bootable USB or CD/DVD to your PC.
• Press "Del" when you are restarting the computer. Boot your computer from "Removable Devices" or "CD-ROM Drive". And then EaseUS Partition Master will run automatically.
• Right-click the disk whose MBR is damaged. Choose "Rebuild MBR" to continue.

• Select the type of MBR with the current operating system. Then, click "OK".

• Click the "Execute 1 Operation" button at the top-left corner and click "Apply" to build the MBR. After that, your computer can boot normally again.

By rebuilding the corrupted or damaged MBR of the system hard drive, if by chance the error still occurs after booting up the computer, continue with the other doable methods to get rid of the error, including to run diagnostics on your hard drive, check bad sectors and repair if found any, and replace the hard drive and reinstall Windows.

All those complementary solutions reply on the same essential tool EaseUS Partition Master. The detailed tutorial on how to use the mentioned functions in it are given on the linked pages.

• Fix 7. How to run a surface test on a hard drive
• Fix 8. How to check and repair bad sectors on the hard drive
• Fix 9. How to replace the hard drive by disk clone