command line - Bootable USB flash drive from iso using windows CMD (I can't find the tutorial...)

In the begining of last year or the end of 2014 I learnt how to make a bootable flash drive from an .iso from a youtube video. I tried to find the video but I can't and it's not in my history.

The video was very simple; first it taught how to format the flash drive using DISKPART and that part I remember, what I don't remember is the last part.
I remember it used the xcopy command with some options and the source and destination, the latest being the flash drive.
As for the source I don't remember if it is the .iso file itself with some options that cause the files to be extracted the same way CD Burning software does or if it was something else.
I don't remember what the options were neither, but I remember one of them was /f

I know the tutorial works because I tried it.
The tutorial was very simple and quick and only used the cmd, no other software.

To sum up:

1. Format the flashdrive to FAT32, assign it a letter...



2. xcopy _some "options i don't remember" .iso_file flashdrive

   
   

   or




3. xcopy "some options i don't remember" "something else?" flashdrive (I think it
   is the first option though)

I saw on some other tutorials that the .iso is mounted and then the files are copied using xcopy; I don't think that was what was in that tutorial. I may be mistaken, but I think that it used only xcopy to extract the files. Maybe there is some option for extracting the files of an .iso like that (if by "extracting the files of an .iso" I sound confusing, what I mean is that when you burn an iso to a cd or flashdrive what you see when you open that cd or flashdrive is several files and not the .iso file your burnt).

Can anyone help me?

Answer

You have two options available to you – in this case both are installing Windows onto a USB key and/or a USB hard drive ...

Format & create a bootable USB key using the CMD prompt & a .iso – from Windows 8.x or 10

I've emphasised the commands by using capitals.

USB KEY

1. insert the USB key


2. Open CMD         - as an Admin


3. DISKPART


4. LIST DISK         - Will display the disks available


5. SELECT DISK *       - Will select the disk  
   ** Ensure you select the right disk **


6. CLEAN


7. CREATE PARTITION PRIMARY


8. SELECT PARTITION *    - The Nº of the partition that you wish
   to make primary


9. ACTIVE           - Makes the selected partition active


10. FORMAT FS=NTFS      - This will take approx. 10 minutes


11. ASSIGN          - This will assign a drive letter
    (we'll believe that it is U:\)


12. EXIT           - To leave "DiskPart"

Find your .iso and right-click to mount it as a virtual drive (we'll use V:\)

1. XCOPY V:\*.* /s /e /f U:\ - Again it will take approx 10 minutes


2. EXIT         - Once the copying has finished .. this will
   EXIT the CMD prompt window

The USB key is now bootable

USB Harddrive

1. insert the USB key


2. Open CMD         - as an Admin


3. DISKPART


4. LIST DISK         - Will display the disks available


5. SELECT DISK *       - Will select the disk  
   ** Ensure you select the right disk **


6. CLEAN


7. CREATE PARTITION PRIMARY


8. SELECT PARTITION *    - The Nº of the partition that you want to be primary


9. ACTIVE           - Makes the selected partition active


10. FORMAT FS=NTFS      - This will take approx. 10 minutes


11. ASSIGN          - This will assign a drive letter
    (again we'll say that it's U:\)


12. EXIT           - To leave "DiskPart"

Find your .iso and right-click to mount it as a virtual drive (we'll use V:\)

1. V:


2. CD BOOT


3. BOOTSECT.EXE /NT60 U:


4. XCOPY V:\*.* U:\ /E /F /H  - To copy the installation files

Once finished you will be able to boot from the external USB HD .. don't forget the boot options (F2 / F12, etc.)