I believe I already posted a how-to regarding installing Windows XP from a USB key flash drive thumb drive. Now we’re onto the next OS – Windows 7. This should work with Vista as well as they use the same boot loader. This will NOT work with XP.
You must have a USB Flash Drive of 4GB or more
You must have the Windows 7 or Vista installation files handy – OEM, Retail, or VL works ON CD OR ISO not just in a random folder
This process will ERASE your Flash drive, so make sure you don’t have anything on there you need to keep
Open the command prompt (Windows Key + R)
If you have any problems with the commands, try typing “cmd” into the Start Menu search box and then press Control + Shift + Enter to activate the admin privileged command promptType diskpart
This will start the disk partition utilitylist disk
This will show all of the disk’s currently in the disk management utility. In most cases Disk 1 will be your USB drive. MAKE SURE that this is the case BEFORE trying any of the following commands.
select disk 1
This selects the disk that you found from the previous command
clean
This clears out the partition tables
create partition primary
This creates a primary partition – primary is needed as a boot device
select partition 1
This selects the primary partition
active
This makes the primary partition active so it can be booted
format fs=ntfs
This formats the device with the filesystem NTFS. It took almost 30 minutes on a 16GB device
assign
This assigns all changes to the device
exit
Exits the utilityKeep the Command Window open though. We’ll be needing it again.
Now insert the CD or mount the ISO image. We need the 7 or Vista files to be mounted as a drive letter. Take note of the drive letter, in my case it’s G:
Also take note of the drive letter for your Flash Drive – in my case it’s F:G: hit enter
cd boot hit enter
bootsect.exe /nt60 f: hit enter
Now copy all of the files from your DVD/ISO to the USB Flash Drive.
Once you’re done, reboot your machine and select the USB HD as your boot device.
That’s it!