How to install Windows 8 (and 7) to external devices

[SionicIon]

We've all been there...we wanted to have Windows follow us to wherever we were. We wanted to boot up our own copy of Windows on any computer. Sadly, it seemed to not be possible. It actually is, and it's a fantastic solution, something Microsoft made possible in Windows 8. But what happens if you don't want to install the Windows Developer Preview on your local HDD before installing to an external device and simply want to test it off the external device? Or what happens if you'd prefer to have a copy of Windows 7 on your external device? All of this is possible already, in fact the feature in Windows 8 is simply the implementation of getting you setup with it.

• Windows 7 cannot adapt to very different hardware, it will simply not boot.
  
• Windows 7 does not have a bootable USB stack.
  
• Windows Embedded Standard 7 can adapt from booting on Intel to all of a sudden booting on an AMD system.
  
• Windows Embedded Standard 7 has a bootable USB stack.
  
• Windows 8 can adapt just like Windows Embedded Standard 7
  
• Windows 8 has a bootable USB stack.
  

Lets get started!

1. Download the Windows Developer Preview, or a Windows 7 ISO. Then extract the ISO to a folder. OR if you have a physical media/external media that has the installation, simply insert/connect the media now.
   
2. Download GImageX, you do not need the WAIK kit, just download this utility by itself. IF you will be using Windows 7, download PWBoot too.
   
3. Download EasyBCD. (Remember you're using this for non-commercial use! So you can download for free, click on the link 'Download free for limited, non-commercial use' at the bottom of the page)
   
4. Start GImageX, click on the Apply tab, browse for source WIM, the find your installation you extracted or inserted/connected to the PC, inside the sources folder is the install.wim, select it.
   
5. Minimize GImageX, repartition your external device so that a partition for Windows exists. The external device must have a partition for Windows but it does not need to be completely repartitioned or bootable at this time.
   
6. Restore the GImageX window to the screen, browse for destination, select the drive. The image index should be 1, but if you unsure, click on the Select button, highlight the edition, and select it. Then click Apply.
   
7. Once it is done, which may take 10-15 minutes or much longer if a slow USB flash drive, you can click Close. Exit GImageX at this time.
   
8. GImageX helped copy all the files of Windows to the external device, you can see that if you browse the drive. But not so fast, we need to install critical boot information. Start EasyBCD.
   
9. Click on BCD Deployment tab, select the partition that resides on the external volume and where you just copied Windows to.
   
10. Click Install BCD. Once successfully converted, click yes to automatically load the new BCD store.
    
11. Click on the Add New Entry tab. Under operating systems, the name will be Windows Developer Preview, OR if using Windows 7, the name will be Windows 7. Select the driver letter. Then click Add Entry.
    
12. That's it! If you're using Windows 8, you can start booting your portable copy right away! OR if using Windows 7, you will not be able to boot and must move on to the next step.
    
13. Start PWBoot, choose Patch existing system, choose External System, choose the drive letter of the Windows 7 installation on the external volume, and then Patch.
    

You're done!

Now how does this all work?

Windows 8 does have something Windows 7 doesn't have. Over the past several months I've been testing several solutions on how to boot Windows 7 from an external HDD and I have full research now to understand more of how it works then I previously did. Windows 7 does not have a bootable USB stack. It simply does not. But Windows Embedded Standard 7 does if you choose that over the normal USB stack during installation. This doesn't mean Windows 7 cannot boot from USB or any other type of external device, it can with a utility we will be using called PWBoot, which will patch the copy of Windows 7 and allow it to boot up. Although this does not replace the USB stack with a bootable USB stack, I'm not quite sure how it works, it may simply void some flags in the boot entry and delay boot-up long enough for USB devices to be recognized, but it does work.

Also, because Windows 7 was never intended for external installations, it is not friendly with new systems that are entirely different to the original system it ran on, for example booting Windows 7 on Intel and then booting on a AMD system. It will not be prepared for this. Yes it may defeat the purpose for some of you, and that is why I recommend using Windows Embedded Standard 7.

Windows Embedded Standard 7 understands that during installation, if you choose the bootable USB stack, it will show USB volumes regarding where to install, plus it will be prepared for any system, regardless if it is Intel or AMD, Windows Embedded Standard 7 will not fail boot-up like Windows 7 will in these scenarios.

I believe the origin of Windows 8's bootable USB stack and it's ability to adapt to other systems without failing on boot-up is Windows Embedded Standard 7. Also note, Windows Embedded Standard 7 is Windows 7, it's just the componentized release of it, meaning you can take parts away or add parts of your own, but it's still Windows 7 and can run everything Windows 7 can run. If you heard of Windows Thin PC, it's origin is Windows Embedded Standard 7, except it isn't as customizable (I do not believe you can choose the bootable USB stack) and it is licensed differently (and it's branded as Windows Thin PC).

(Note: the newest PWBoot release is extremely easy...I didn't notice until I made this how-to...the utility hasn't been updated for a long time...until a week ago. But this is the proven way before that new version came out, I still would not trust Windows 7 for booting on all sorts of systems, so don't get carried away with that fancy new wizard that automates a lot of this process! and again, windows 8 doesnt need PWBoot patching in the first place.)

Cheers! :cool:

[Shaun N.]

Hasn't this already been done?