Missing Operating System

Many users reported the occurrence of Missing Operating System on their computer screen. Missing Operating System occurs with black screen and error message saying:

“Missing operating system” or “Operating System not found”

Missing Operating System error usually occurs when your start your computer.

Possible Causes of Missing Operating System:

• BIOS did not detect the hard drive.
• Damaged hard disk.
• Faulty data cables.
• Corrupted Windows MBR (Master Boot Record).
• Partition of hard disk having the Windows MBR is no longer active.

Methods to Solve Missing Operating System

Method 1: Rebuild BCD

• Boot from Windows installation media.
• Select language and region and click on Repair computer.
• For Windows 7:
  • Select first item and then the Windows 7 system
  • Click Next and then click on Command prompt.
• For Windows 10:
  • Select Troubleshoot and then select Command Prompt.
• Type bootrec /rebuildbcd in command prompt and hit
• Enter Y, if asked to add a new installation to boot list.
• Close command prompt and retsrat your computer.

Method 2: Check Cables

Missing Operating System can occur due to loose connection between hard drive and computer. Check SATA cable and power cable and if any damage to cables is found replace the cable.

Method 3: Repair Master Boot Record

• Insert the Windows Operating System Disc or plug in the USB having Windows OS.
• Hold power button for 5 seconds, this will turn off the PC. Now press the power button again to turn on the PC.
• Press Enter when prompted to Boot from CD.
• Press the R to start the Recovery Console.
• In command prompt type FIXMBR and press the Enter
• Press the Y and then press Enter when asked if you want to write a new MBR.
• Restart the PC once the MBR is successfully written.

Method 4: Set the System Partition Active

• To open Command Prompt repeat the first three steps from Method 1.
• Type the following and hit Enter after each:

diskpart

list disk

• Type select disk # (# is the number of the disk where you have installed your system) and press Enter.
• Type list partition and press Enter, this will open list of partitions in the disk.
• Type select partition # (# is the number of the System Reserved partition).
• Type active and hit Enter.
• Type exit to exit diskpart.
• Restart your computer.