Due to the enormous amount of software installs and uninstalls I decided it’s about time to reinstall my desktop machine. Having no spare DVD around my installation media of choice was a USB key.
Installing windows 7 from USB key is quite fast actually. Here is how to prepare Windows 7 bootable USB.
NOTE: My installation was Windows 7 Professional SP1 x64. After completion of this process the space occupied on the USB key was 3,11 GB.
You will need a flash drive around 4 GB, an ISO image or DVD of Windows 7 and a machine running Windows XP or later. Also an archive tool able to extract ISO files. I use 7-Zip.
Preparing the installation media
1. Formatting the USB drive
Plug in the USB memory stick, right click on the drive in ‘Computer’ and select ‘Format…’. I recommend doing complete format by removing the check box next to ‘Quick Format’ option.
Depending on the drive size and speed the format will take some time.
2. Making the USB drive bootable
For this step we will use a command line utility called Diskpart. It’s bundled with every Windows version from 2000 onward.
To start Diskpart, click on the Start button and type diskpart. The diskpart utility will appear. Give it some time to load and enumerate your drives.
NOTE: For complete list of commands that the utility supports type: help at the DISKPART> command prompt.
To list your drives type list disks. From the list of your drives find the USB stick by comparing the size of the drive with the size of your USB stick. In my case the flash drive was ‘Disk 3’
At the ‘DISKPART>’ command prompt select your USB drive by entering the following command where # is the drive number of your flash drive:
DISKPART> select disk #
Now type in the following sequence of commands:
DISKPART> clean DISKPART> create partition primary DISKPART> active
Close the utility by typing:
Your flash drive is now bootable. It’s time to copy the windows installation files on it.
3. Coping the Windows 7 installation
Extract the Windows 7 iso image to a location of your choice. If you are using 7-zip right click on the .iso image select 7-zip and from the sub menu select ‘Extract files…’
NOTE: If you are turning Windows 7 DVD in to a bootable Flash drive installation just copy the contents of the DVD on the flash drive.
Copy the contents of the extracted .ISO file on your USB drive as you normally would.
This method is applicable also for Windows 2000, XP and Vista.