Jump To: Support > KB > Windows > USBInstaller

Creating bootable USB drive to install Windows

1. First find a big enough USB memory stick (min 8GB) and plug it in. Take a careful note of the drive letter (e.g. G: for this walkthrough) and its size (e.g. 8GB)
2. Get the ISO image for the Windows operating system you want build an installer for
3. Mount the ISO image (can be done directly on Windows 10 and later by right-clicking on the ISO and choosing Mount, but on older operating systems we recommend Pismo File Mount
4. Take a careful note of the drive letter the ISO image is mounted on (with Pismo File Mount you can choose the letter). e.g. J: for this walkthrough:
   
5. Open an elevated command prompt, by finding Command Prompt on your Start Menu, right-clicking on it and choosing Run as administrator
6. Type diskpart, then list disk at the command prompt:
   
7. Note the disk number of your USB drive, in the above example it is disk 2
8. Type select disk followed by the disk number and then type list disk again:
   
9. Double-check that the correct disk is selected with an asterisk
10. Type the following as separate commands into diskpart.
    For MBR/BIOS:
    clean
    create partition primary
    select partition 1
    active
    format fs=ntfs quick label=Installer
    exit
    

    [$[Get Code]]
    
    For GPT/UEFI:
    clean
    convert gpt
    create partition primary
    select partition 1
    format fs=fat32 quick label=Installer
    exit
    

    [$[Get Code]]
    
    
11. For MBR/BIOS only, change to the drive letter of your mounted ISO image by typing the latter followed by colon (in this case J:) and then change to the boot subfolder with cd boot:
    
12. For MBR/BIOS only, make the USB drive bootable by running bootsect /nt60 G: where G: is replaced by the drive letter of your USB drive:
    
13. Copy all the Windows installer files onto the USB drive with xcopy by running xcopy J:\*.* G:\ /E /H /F /C. Replace J: by the drive that your ISO image is mounted on. Replace G: by the drive letter of your USB drive
14. Wait quite a long time
15. For GPT/UEFI only, you will probably see a File creation error when trying to copy \sources\install.win as the file is too large to go on a FAT32 filesystem (which has a 4GB limit):

    J:\sources\install.wim -> G:\sources\install.wim
    File creation error - The parameter is incorrect.
    

    
    To fix this use dism /Split-Image /imageFile:J:\sources\install.wim /SWMFile:G:\sources\install.swm /FileSize:4096 to split the file into fragments of no more than 4GB (replacing J: and G: by the source and destination drive letters as above):

    C:\Windows\system32>dism /Split-Image /imageFile:J:\sources\install.wim /SWMFile:G:\sources\install.swm /FileSize:4096
    
    Deployment Image Servicing and Management tool
    Version: 10.0.19041.844
    
    The operation completed successfully.
    

    
    After the copy has completed (will take a long time), you can the dir command to check:

    C:\Windows\system32>dir J:\sources\install*.wim G:\sources\install*.swm
     Volume in drive J is CPBA_X64FRE_EN-US_DV9
     Volume Serial Number is D1C4-46EA
    
     Directory of J:\sources
    
    08/09/2022  04:25     5,011,673,968 install.wim
                   1 File(s)  5,011,673,968 bytes
                   0 Dir(s)               0 bytes free
    
     Volume in drive G is INSTALLER
     Volume Serial Number is C2B7-F054
    
     Directory of G:\sources
    
    14/11/2022  13:09     4,294,964,054 install.swm
    14/11/2022  13:06       685,661,744 install2.swm
                   2 File(s)  4,980,625,798 bytes
                   0 Dir(s)   4,591,173,632 bytes free
    
    
16. If you have extra drivers (e.g. for disk and RAID controllers) that you will need to install Windows, you can copy them onto the USB stick into a Drivers folder
17. Once completed, you can close the command line window and then eject the USB drive and your ISO image

References

• Splitting install.wim