Installing Windows 7 To a USB External Hard Drive

Creating a bootable USB disk with Windows 7 requires a few more steps than the one with Linux. Here we show you how in a few simple steps

STEP 1: When you attempt to install Windows 7 on an external drive, you get “Windows cannot be installed to this disk” error. So to install Windows on an external hard drive, create two folders named Windows Files and WAIK Files on your desktop. For installation process, you need these three files: Bcdboot.exe, Bootsect.exe, and Imgex.exe. These files can only be obtained by installing Windows Automated Installation Kit for Windows 7 on your Windows PC. Once you installed the WAIK go to Windows installation directory and simply search for them. Copy these three files to WAIK Files folder that you have created on the desktop.

STEP 2:
Now extract the Windows 7 Installation files from ISO file or copy all the contents of Windows 7 installation DVD to the Windows Files folder created at the desktop.

STEP 3:
The next step is to run Installer.cmd file as Administrator (Right-click on installer.cmd and select run as administrator).

STEP 4:
Now, press Enter key to browse to the install.wim file present in the Windows Files folder (Windows Files/ Sources/ install.wim).

STEP 5:
Now, you need to select the Windows 7 edition that you want to install on an external hard drive as shown in the screenshot.

STEP 6:
The next step is to enter your External drive’s drive letter which you can easily find out under My Computer. Enter the drive letter and press enter key.

STEP 7:
Now, it asks for ACTIVE partition drive letter. Generally “C” is the active partition. You can find the active partition by opening Windows Disk Management tool (to open it go-to run and type diskmgmt.mscin).

STEP 8:
Finally, it will ask you for the drive letter which you have entered to install Windows 7. As you are installing Windows 7 to an external hard drive simply type “Y” without quote and press Enter key.

STEP 9:
Finally click Enter key again to start extracting the Install.wim files. This might take a few minutes. Once done, you will be asked to reboot your PC to continue the normal Windows 7 installation procedure.

STEP 10:
Once rebooted, follow the normal Windows 7 installation procedure to complete Windows 7 installation on an external hard drive. Your PC will be restarted twice or thrice during the installation. The installation might be slow as it installs files on the USB drive.
THE PRE-REQUISITES:
• NTFS formatted external hard drive with minimum 15 GB free space
• Windows 7 ISO file
• Windows Automated Installation Kit