How To Re-Create A Bootable ISO From Extracted Windows Installation Files


There are many reasons why you might want to modify a bootable ISO image file. One of the reasons is to create a modified ISO of Windows 8/8.1 install disk so you can skip the product key during an installation step. In our original guide on how to install Windows 8/8.1 bypassing product key we did not elaborate the steps involved in

extract the files from Windows 8 ISO file, add a file named ei.cfg in sources folder

This one line of instruction is actually much more complicated for no power user. Even for people who know what needs to be done, they might lack the tools to accomplish this task.

So here is a step-by-step guide on how to modify a Windows ISO file with 100% free tools available for the general consumer

(no cracked or paid software necessary)

First you need to extract the ISO file into its own folder. Use 7-zip, you can right-click on the ISO file and go to Extract to “en_windows_8.1_with_update_x64_dvd_4065090” (or whatever the ISO file name it was originally in).


Now go download and install ImgBurn if you haven’t.

Choose the option “Create image file from files/folders


Before proceed ensure your have added the necessary ei.cfg file under the sources directory.


Now back to ImgBurn, Source will be the folder contains all the Windows install file. Destination, can be any place where you normally place ISO files. The important steps are on the right sections under Advanced → Bootable Disc

Ensure checked “Make Image Bootable

Under Boot Image you want to select the file called under boot directory

Sectors To Load > change to 8

2014-12-08_1543_003 2014-12-08_1543

Now everything is ready to go, hit the button to start the process. This will prompt for a confirmation on Volume Label creation. Leave everything default will be okay.


Yes to continue.


Shortly ImgBurn will create a bootable ISO file based on the selected folder. You can now use this ISO image to install a brand new Windows 8 machine that will allow you to not enter any product key during the installation setup.



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