How to Create a Windows 7 Bootable USB Disk

How to Create a Windows 7 Bootable USB Disk: This article has been updated and re-posted.

This blog post is intended to act as a guide to my fellow classmates who own mini-laptops that have no optical drive and are thus faced with the option of installing Windows 7 from a bootable flash drive or an external optical drive or external hard disk. I’ve helped a few since this has always been an issue. I am sharing what I know with them and everyone else. I love using the command prompt and so this procedure is for using the command prompt to create a bootable flash drive. I know there are various software available out there for doing this task in a quick manner but hey, this is the surest way of creating a bootable USB disk without disturbing your computer system’s registry with so many needless entries in the name of installing a program for creating a bootable flash drive. However, apart from my classmates, others who may find this post useful please recommend it. So how do you create a Windows 7 bootable USB disk?

Requirements:

Have a USB flash drive that can accommodate fully the size of the Windows 7 version you want to install. For instance, the .ISO file for Windows 7 Ultimate for 32-bit computers is about 2.32 Gb and that of the 64-bit version is 3.47 Gb. Therefore, in my case, for the 32-bit version and the 64-bit I’ll require at least a flash drive of 4 Gigabytes for each of them.

Procedure

• Plug in the USB flash drive into a high speed USB port on your computer. (Check your Device Manager to determine which port on your computer is the high speed USB port. However, other USB ports may work fine as well but I highly recommend the high speed USB port.)

The Windows 7 Start Menu. Run the command prompt with administrative privileges

• Go to Start Menu > Accessories > Command Prompt (as shown above) and right click on Command prompt choosing Run as Administrator from the resulting drop-down menu.
• In the cmd.exe window type diskpart then hit ENTER (no space in the command “diskpart”)

Type “diskpart”

• Type list disk (there’s a space in the command “list[SPACE]disk”) then press ENTER (subsequently, after every step from here hit the ENTER button). Take a look at the size column and figure out which disk number your USB drive is. In my exhibit here, my disk is disk number one.

• Depending on what your disk number is, type select disk 1 then hit the ENTER button.

Type “select disk 1″ (in this example it is disk one, yours could be 2, 3 or whatever number)

• I hope the flash drive or USB device you have plugged in and intend to use as a bootable drive is empty, else back up all your stuff since this process will completely wipe all the contents of the drive.Type clean then press ENTER.

Type “clean” (this option cleans your flash drive so make sure you had backed up any contents prior to running htis command)

 

This process now prepares the USB drive for the OS files and makes sure it is bootable.

• Type create partition primary then press ENTER.

Type “create partition primary”. Be careful not to type ‘create primary partition’ as this won’t work.

• Type select partition 1 then press ENTER.

Type “select partition 1″ then after pressing ENTER Type “Active”. This makes your selected partition the active one and ready for formatting.

• Type active then press ENTER.
• Type format fs=fat32 then hit ENTER (note that there is a SPACE in the command “format[SPACE]fs=fat32”)

Wait while your flash drive is formatted

 

(If you wish to format your USB drive to another file format like NTFS then you’ll later have to run this command: Bootsect.exe/nt60 M: (there is a space in the command i.e. … nt60[SPACE]M: ) to put boot manager compatible files onto your USB flash drive to make it a bootable device. Remember M: represents the drive letter your USB flash drive has been assigned by the computer and you should replace it with the drive letter of your device accordingly. My exhibit device is herein assigned M: . I however don’t recommend this process of formatting to NTFS format) Give your computer time to format the USB flash drive as this could take a while.

• After you have formatted to whatever file system you chose in procedure 10, type assign then hit ENTER. (this assigns a new drive letter to the USB drive). An AutoPlay window like the one that pops up when you plug-in any plug n play media will appear (like in the screen shot below).

Your drive has been successfully assigned a drive letter and mount point.

• Note the assigned drive letter, in my exhibit case it is M: , close the AutoPlay window then type exit in the cmd.exe window.

You are done creating a bootable USB flash drive using the command prompt!

The next step is to now copy the Windows 7 .ISO or installation files to the bootable disk. This can be done in 3 ways:

• Using a virtual drive mounting program like Power ISO, Ultra ISO, Daemon Tools Lite or Pro etc. to mount the file if you are using a .ISO file.
• Extracting the files from the .ISO file using an extracting program like WinRAR and simply copy them to the USB drive.
• This is the interesting part, the third alternative way is to use what we have been using all along, the command prompt…

- Open the command prompt once again with administrative privilege

- Type xcopy f:*.*/s/e/f hm: (there’s a space(s) “xcopy[SPACE]f:*.*/s/e/f[SPACE]hm:”) and press ENTER (Replace f: with the drive letter for your Windows 7 DVD     (the one you are copying the Windows 7 installation files from or if you just had the .ISO file then the drive letter of the virtual drive where you mounted your .ISO file), and m: with the drive letter for your USB flash drive).

Wait for the files to be copied. install.wim should take long to be copied to your USB flash drive since it is simply the largest of the Windows 7 installation files.

Installing Any Edition of Windows 7

If you have followed the steps accurately so far, then fear not, this is the last part of “how to create a Windows 7 bootable USB disk”.

There are those Windows 7 installation DVDs that come with an option to select the version of Windows 7 you would like to install on your computer e.g. choosing between Windows 7 Home Premium and Windows 7 Professional or Windows 7 Professional 32-bit and Windows 7 Professional 64-bit. This simple procedure is to make sure that should you have copied your Windows 7 installation files from either of such disks, the bootable USB drive you have created should be able to give you the same option of choosing which operating system to install on your computer and not automatically install the first option by default. If you copied from a DVD that had only one version of Windows then skip this part and disregard the procedures listed below.

• In the command prompt type del m:sourcesei.cfg then press ENTER (where m: here, as I stated earlier, is your bootable USB flash drive). — NB: THIS PROCEDURE IS NOT NECESSARY SINCE BY COPYING WINDOWS 7 FILES FROM A MULTIPLE INSTALLATION DVD OR VIRTUAL DISK SHOULD MAKE YOUR USB FLASH DRIVE ABLE TO GIVE YOU AN OPTION TO CHOOSE WHICH WINDOWS 7 VERSION TO INSTALL.
  

That is the whole procedure. For any queries, you know where to find me: E-mail, tweet or comment.