The following article will explain how to check your USB flash drive for if it’s bootable. There is no software needed, no download, just a couple of simple commands in your Windows 10 operating system.
A master boot record (MBR) is a special type of boot sector at the very beginning of a partition storage device like a fixed disk (hard drive) or removable drive (USB thumb drive). The MBR contains executable code to function as a loader for the installed operating system. This loader turns over the functions of the hardware (mother board bios) and passes that loading responsibility off to the operating system (Windows).
This is how you check if your USB is bootable, or not:
First, please have only the one USB stick connected which you want to check if it’s bootable. It’s not required to do this, but will my the instructions below a bit easier to follow, that’s all.
Using the Windows search function copy and paste this into the search field and click Enter
The screen shot below will pop up after you click Enter. Using the image as a reference, select “Disk Management” under the “Storage” folder“. In the middle of the dialogue box you will see the drive letter associated with your USB flash drive. In the middle of the box you will probably see the USB listed two different times. The top portion of the box, the USB will be listed along with other devices, like your hard drive and optical drive. The bottom portion of the box, the USB will be shown as “Removable“
Once you’ve determined which drive letter is your USB drive, you may Right Click on the drive letter and select Properties.
A Properties dialogue box appears giving you the option to select any one of the devices show in the previous window (the Disk Management window). From this dialogue box, click the Hardware tab and select the “Mass Storage USB Device” by a single click. Then click the Properties button at the bottom.
The last dialogue box are the Properties of your specific flash drive.
Click the Volumes tab at the top, you then must click “Populate” to get the device information. . The “Partition Style” will read either Master Boot Record (MBR) or the field will be empty.
If the above information isn’t detailed enough for the information you are looking for, the next step is to use a hex editor and check if the boot strap code is actually in the Master Boot Record. This is a bit more detail and the guys at Hakzone did a really good job of summarizing how this would be done using a hex editor program.