Creating a Windows7 Installation Bootable USB Key

How to create a Windows7 installation bootable USB key, after all, who wants to carry around DVD’s anymore (and does your computer even have one)?

Distilled from this post.

Fired up my bootcamp partition in Parallels
Connected Window7 ISO to virtualiser via Devices -> CD/DVD -> Connect Image [Alternatively, if you're running Windows natively you could mount the image some other way]
In windows, open an Administrator command prompt (by typing ‘cmd’ in the run dialog, and pressing Ctrl+Shift+Enter)
[NB. I followed the above guide for this, but I'm not convinced it was actually nessesary – you can probably just skip this step and go right to reformatting the USB Key to NTFS. If you do take this step, be careful with these commands and make sure you know what you are doing because it's really easy to nuke an entire HDD if you get it wrong.] Re-partition the USB key with diskpart:
```
diskpart
list disk
select disk X  # where X is your USB key – don't get this wrong!!!!!
clean
create partition primary
select partition 1
active   
assign # this mounts the device
```
Format the USB key drive to NTFS, I used Windows to do this (right click -> Format), not diskpart

Select the Windows7 CD, e.g. e:. And run:

e: # where e: is your Windows DVD
cd boot
bootsect.exe /nt60 h:  # where h: is your USB key
# now it should be bootable

Done. I was able to boot this installation USB device on a 2008-era BenQ joyboook.