How to Create a Bootable Windows Vista or Windows 7 USB Flash Drive

You can create bootable Windows Vista or Windows 7 on USB flash drives as long as the flash drive has the capacity to store the entire Windows OS installation files. You need a 4 GB USB flash drive to have enough space to fit the entire Windows O/S installation file on the drive.

Before you begin it is important to understand that any data on your USB flash drive will be permanently deleted. Save any important documents on the USB flash drive to another location before proceeding to the next section.

To create a bootable USB flash drive, insert the device into a USB port, and then use the DiskPart utility to prepare the device.

The commands you need to run are as follows:

1. After the USB flash drive has been recognized and inserted to the computer, click the button, type Diskpart, and hit Enter key.
   
   
   
2. At the DiskPart Command Prompt window, type list disk and hit Enter key.
   
   
   
3. Take a note of the Disk # number of your USB flash drive. You can easily find it by looking at the size column.
   
   
   
4. Once you have the disk number, type select disk # and hit Enter key. Replace the # hash symbol with the actual disk number, such as 1.
   
   
   
5. Type clean and hit Enter key to destroy any partitions, file system, and data that may currently be on the USB flash drive.
   
   
   
6. Now it is time to create the partition. Type create partition primary and hit Enter key.
   
   
   
7. Type active and hit Enter key.
   
   
   
8. Type Format FS=Fat32 Label=WinBoot Quick and hit Enter key. This command performs a quick format and labels the USB flash drive as "WinBoot".
   
   
   
9. Type exit and hit Enter key. To close the DiskPart window. Your USB flash drive is now prepared for the next phase.
   

Write a New Boot Sector to USB Flash Drive

The commands you need to run are as follows:

1. First open the Command Prompt by clicking the button, type Cmd.exe, right click the Cmd.exe, select "Run as administrator" from context menu.
   
   
   
2. Insert the Windows Installation DVD into your PC or mount the Windows Setup ISO image.
   
   
   
3. At the elevated administrator Command Prompt change the Command Prompt working directory path to the Boot folder that resides on the Windows Installation DVD or mounted Windows Installation ISO image, where bootsect.exe executable file lives.
   
   
   
4. Type Cd /d  X:\Boot, replace the X: drive letter with the drive letter of the Windows Installation DVD or drive letter of the mounted Windows Installation ISO image.
   
   
   
   
5. Write a new boot sector to the USB flash drive by entering bootsect  /nt60  X: /force, where X: is the drive letter of the USB flash drive.
   

Note: Some USB flash drives do not support this preparation process, and you might not be able to make the device bootable in this way. The devices that do not support this process are typically set so they are recognized as removable media devices and not USB disk devices. Because of this, you might need to refer to the device manufacturer’s Web site for formatting documentation and tools.





Copying the Windows Installation Files

The final step, now that you have your USB flash drive prepared, it's time to copy the Windows Installation files to the USB flash drive.

1. Insert the Windows Installation DVD into your PC or mount the Windows Installation ISO image and navigate to the drive on your computer that has the Windows installation files.
   
   
   
2. Select all the files and folders, and then right-click and select Copy from the context menu.
   
   
   
3. Navigate to the root of the USB flash drive, right-click and click Paste from the context menu.
   

The copy process of the Windows Installation file and folders can take a number of minutes, but after it has finished you can install the Windows OS quickly on machines with USB flash drive.




You can also copy all the Windows Installation files to the USB flash drive that you’ve been preparing with Xcopy command. In this example, the Windows Installation ISO image is mounted with the drive letter V and the  X drive letter assigned to the USB flash drive.

Knowing this, type the following command and press Enter:





You might also want to check out below tutorial.

How to Create a Bootable Windows 8, Windows 8.1 or Windows 10 USB Flash Drive