Installing Free Windows 8.1 – Step4: Convert ISO File to Bootable USB Drive
The free Windows 8.1 download file will be in ISO image format and hence can’t be executed directly to install the operating system. You need to convert the ISO image file into a bootable flash USB drive or burn into a DVD to start Windows from a USB drive or a DVD.
Creating Bootable Flash USB Drive or DVD
In order to create a bootable USB drive Microsoft offers a free USB/DVD tool which you can download here for free. Though the name of the tool suggests Windows 7 it will still work good for Windows 8.1 as well.
You need a USB with a minimum capacity of 8 GB (recommended to have 32 GB) and ensure the USB is not having any data. All the existing data in your USB will be deleted since it is necessary for the tool to format your USB.
Once you installed the tool, insert your USB, run the program, select the saved ISO image of Windows 8.1 and select “Begin copying”. The program will start copying the ISO file into your USB which will take around 10-15 minutes.
The tool formats your USB with NTFS file system which sometimes may not work with your computer. In that case, once the USB flash drive is ready, copy all the files to your PC and manually format the USB with FAT32 file system and copy back the files again to USB.
You also can burn the ISO image file into bootable DVD or BD disc using this tool.
If the Microsoft’s USB/DVD maker tool does not work for you for any reason, then you can use another free USB maker tool. Download the free WinUSB Maker here and the procedure is same as explained above: Run the program, Select ISO file, insert USB and start making a bootable drive.