How to Troubleshoot the ISO in UNetbootin

If the process completes successfully, but your PC won't boot from the USB flash drive, check the boot options in the computer's setup program.

ISO images compress all of the files on a CD or DVD into a single file. Under normal circumstances, creating a bootable flash drive in Windows requires jumping through a lot of hoops, but UNetbootin simplifies the process. Errors can occur, however, when UNetbootin doesn't recognize the ISO image; if the program can't detect or read the file it's supposed to be writing to disk, then the entire process comes to a halt. In some cases, though, the problem isn't the ISO file, but the USB flash drive instead. Determining the source of the error requires a little bit of troubleshooting.

Instructions

1. Confirm that the ISO image has finished downloading in full. Click "Start." Click "Computer." Go to the folder where the ISO file is stored.

2. Right-click the file, then click "Properties" to see the full size of the file. Go to the website that you downloaded the file from and check the file size of the download. If the size of the ISO stored on the hard drive is not equal to the size of the file available on the website, restart or resume the download.

3. Return to the Properties window if the files are identical in size. Uncheck "Read-Only" and click "Unblock," if possible. Click "OK" to close the window.

4. Disconnect your USB flash drive. Click "Start." Click "Computer" to open Windows Explorer. Reconnect the flash drive to the USB port. Take note of the letter assigned to the device when it appears in Windows Explorer.

5. Return to UNetbootin. Click "Diskimage" and select "ISO" from the drop-down menu. Click "Browse." Select the ISO file and click "Open."

6. Choose "USB Drive" from the Type drop-down menu. Click "Drive" and select the correct letter from the menu. Click "OK" to burn the ISO to the flash drive. If an error occurs, or if the drive isn't available, return to Windows Explorer. Right-click the flash drive and click "Format." Select "FAT32" from the drop-down menu. Click "OK" to delete the files off the drive and format the file system in FAT32.

7. Return to UNetbootin and again attempt to write the image to disk. If another error occurs, the ISO file may be corrupted or may not be a valid disk image.

Resources

• UNetbootin