The most common reason for this is that the system partition was accidentally made inactive, often after using tools like DiskPart or other partition managers. Other possible reasons include hard drive problems, missing boot files, or the wrong drive being set as the main boot device in BIOS. Now that you know the causes, let’s discuss the error.
1. Verify that BIOS Detects the Windows Installation Hard Drive
Before trying any fixes, it’s important to check if your BIOS can see your system drive. If your BIOS doesn’t detect the drive, Windows won’t be able to start at all. This step makes sure your disk is properly connected and recognized by your computer’s hardware, and helps you rule out any problems with the drive or the port it’s plugged into.
2. Set BIOS to Default Settings
Sometimes, a simple reset can fix hidden problems. Restoring the BIOS to its default settings will clear any custom boot order or changes to disk modes that might stop your system from finding the active partition.
3. Repair System Files with Startup Repair
A damaged boot environment can’t guide Windows to the right partition, even if it’s set as active. Startup Repair fixes missing or broken system files, boot configuration data (BCD), and important services needed to start up your computer. It restores the connection between your computer’s firmware and the Windows loader.
4. Make the System Partition Active
Marking the correct partition as “active” tells your computer where to look for the files it needs to start up. This step makes sure the BIOS passes control to the right part of your hard drive, where the bootloader is stored, so Windows can load properly. Restart your computer and check if the issue is resolved.
4. Repair MBR
A damaged boot map leaves your computer confused about where to start—repairing the MBR (Master Boot Record) puts the important startup instructions back in place. This helps your PC find the right area on your hard drive and load Windows correctly. If you receive an error during MBR repair, such as: The selected disk is not a fixed MBR disk. The ACTIVE command can only be used on fixed MBR disks. You can refer to the Fix: The Selected Disk is not a Fixed MBR Disk article to know more.
