In this step by step tutorial you will learn how to make a Bootable Windows 7 USB Installation using Command Prompt with Administrative Rights. This is a good way to carry less, and install more. You can also copy or backup other files on the same Windows 7 USB Drive. This tutorial applies for both Windows 7 versions (x86 or x64).
If you want a super fast install, is highly recommended to use a USB 3.0 Flash Drive. Due to their lack of speed, USB 2.0 Flash Drives will take much more longer, around 1-2 hours for installing Windows 7. The average time on USB 3.0 is around 15-20 minutes.
To access Command Prompt, go to Start - All Programs - Accessories, Right Click on Command Prompt and select Run as Administrator.
Now we must clean the USB, create a new active partition and format him as NTFS.
To do that, after running Command Prompt with Administrator Rights, you must write a series of commands:
DISKPART LIST DISK
First command DISKPART opens the Partition/Disk Manager where you can manage all your available drives (external and internal).
Second command LIST DISK will list all drivers. It is very important to select the right disk which represents your USB Drive, because you will delete and format your USB. Pay attention when selecting the disk to avoid deleting another drive. If you know your USB size this will not be a problem.
Next select the USB Disk. In our image above, USB is Disk 5. On your computer, this may be different so make sure you select the right disk.
SELECT DISK 5 CLEAN
After you selected the right disk, use the CLEAN command to clean the USB of any active partitions.
Now you must create a new partition inside the USB Disk and set it as primary. After this, you must select this new partition, which is 1 (only one created and is not the same number as the disk number) and make it active.
CREATE PARTITION PRIMARY SELECT PARTITION 1 ACTIVE
Next we need to format the USB Disk, using NTFS file system to write large files (over 4GB). This process will take some time, between 10 to 30 minutes, depending on the USB Size and Speed. When done, use the ASSIGN command to assign a letter to your USB Drive.
FORMAT FS=NTFS ASSIGN EXIT
After assigning the letter, a popup with AutoPlay will appear. Your USB is now ready. To exit from DISKPART simply type EXIT.
Now we must make the USB Bootable by extracting the BOOTCODE from the original Windows 7 DVD. Make sure you have your Windows 7 DVD inside the DVD-ROM Drive to begin the bootcode extraction.
In the picture below our DVD-ROM is Drive I: and USB is Drive L. Yours may be different.
I:/BOOT/BOOTSECT.EXE /NT60 L:
Your USB Drive is now bootable.
All you have to do now is to copy all the files from the Original Windows 7 DVD and paste them to USB Drive. Make sure that all hidden files are visible. Just enable the option "Show hidden files and folders" from Folder Options. If you don't know how to do that, follow this article.
Please note that this may take some time if you have a USB 2.0 Drive. Anyway, just to know USB 2.0 is half slower than a USB 3.0 and the Windows 7 Setup will take much longer on USB 2.0.
And you are done. Your USB is Bootable. Now safely remove the USB using the tray icon, restart your computer and try to boot your Windows 7 USB.
Usually you must press F11 when you first turn on your computer, to access the BIOS Boot Manager or you can simply go to BIOS and set the First Boot Drive to USB.
An alternative to this trick is to install Windows 7 USB / DVD Tool from Microsoft Store which is free for download and very easy to use. This will work only if you have a bootable .ISO Image from your Windows 7 DVD.