How to Fix for Boot Device Not Found Issue in Windows 10/8/7

When the computer appeared error of “boot device not detected”, which occurs during the process of booting the operating system. such as “No bootable device – insert boot disk and press any key”, “Boot Device Not Found. Please install an operating system on your hard disk…”, “No Boot Device Found. Press any key to reboot the machine” or “no boot device is available”. Please look at the following pictures to know much information about this issue.

How to Fix Boot Device Not Found Issue

Firstly you need to check whether your hard disk has a good state or not. Usually, the related bootable device not found issues are caused by the damaged or faulty hard disk. Therefore, it is suggested to test your hard drive of using a reliable  third-party tool – MiniTool Partition Wizard.

As partition and disk management software, it is designed to manage disks and partitions well, including resizing partition, doing conversion between NTFS and FAT32, doing conversion between GPT and MBR, migrating OS to SSD, rebuilding MBR, copying disk/partition and so on. This tool has “Bootable Media” feature which enables you to manage your disks and partitions when there is no operating system or system fails to boot.

Step 1: After building a bootable disc and booting your computer from the device, you will go to an interface. Click “Partition Wizard” to launch this tool.

Step 2: Then you will go to the main interface of MiniTool Partition Wizard. Select the target disk, and then click this feature “Surface Test” in the left pane.

Step 3: Then click “Start Now” button to start a disk test. During the process, MiniTool Partition Wizard will mark bad sector “red“, and mark disk block without error “green“.

After a disk test, if there are many bad sectors, in order to ensure your data security, you had better backup the important files on the target hard disk. Here MiniTool Partition Wizard V 11.5 is also useful to do this work after performing CHKDSK operation.

You can use its two features for the backup:

Copy Disk: it enables to clone the entire disk data to a new hard drive which should be larger than the used disk space of the source disk. This feature adopts sector-by-sector mode during the disk copy.

Copy Partition: if your important files are saved to a partition, this function is recommended.

You can choose one to make a backup according to the real situation.

If the above methods can’t solved your errors, you can try to repair MBR or fix boot sector. As you know, if MBR or boot sector is damaged, your PC will fail to boot with bootable device not found issue. The MBR is a part of computer boot hard disk which contains executable code to function as a loader for the operating system and it can help PC boot successfully. Once it is damaged, the error occurs. Therefore, the important thing is to repair master boot record or boot sector. In this case, MiniTool Partition Wizard Bootable Media also can offer a help.

Step 1: Please boot PC from the bootable disc you have built. Then in the main interface of MiniTool Partition Wizard, select the target hard disk to click “Rebuild MBR” from “Check Disk” menu.

Step 2: At last, click “Apply” button to finish fixing boot sector and MBR.

After fixing boot device not available problem, the operating system is in the healthy state now. You’d better make an OS migration for backup. In order to ensure the system runs normally, when system unbootable issue occurs again, OS backup is necessary to recover OS to the previous point.