How to Put Bootable ISO Images on a USB Flash Drive
Although Microsoft provides an ISO image of Windows 8.1 for download during checkout, you cannot begin installation unless you burn the ISO image to a DVD. In instances where you don’t have access to a blank DVD, transfer the files within the ISO image to a flash drive for installation via USB. To create a bootable flash drive, however, you must use a utility called Windows 7 USB/DVD Download Tool, available free of charge from Microsoft.
1 Insert a USB flash drive
Insert a USB flash drive with at least 4GB of storage capacity. Since all data stored within the flash drive gets permanently erased while transferring the ISO image, back up any important files within the flash drive before proceeding.
2 Download the Windows 7 USB
Download the Windows 7 USB/DVD Download Tool from the Microsoft Store (link in Resources). After installing, double-click the “Windows 7 USB/DVD Download Tool” shortcut on your desktop. On the User Account Control pop-up box that displays, click “Yes.”
3 Click Browse and then select the Windows 8.1 ISO file
Click “Browse” and then select the Windows 8.1 ISO file from your hard drive. Click “Next” to continue.
4 Click the option
Click the option labeled “USB Device.”
5 Click Begin Copying
Click “Begin Copying.” On the pop-up box that shows up, click “Erase USB Device” and then click “Yes.” The Windows 7 USB/DVD Download Tool automatically formats the flash drive and then copies the files in the ISO image to the flash drive. Once the “Bootable USB Device Created Successfully” message displays, click “Start Over” and then click “Close.”
- Since certain flash drives feature less storage space than advertised, the Windows 7 USB/DVD Download Tool may notify you of a lack of sufficient space. In this case, use a flash drive with at least 8GB of storage capacity.
- The download link is located under the Installation section on the Windows 7 USB/DVD Download Tool page.
- To install Windows 8.1 from the bootable USB flash drive, press the function key displayed onscreen next to “Boot Menu” during computer startup. If your computer displays no such instruction, consult your computer's manual to find the correct key. Usually, the Boot Menu shows up when pressing the F10 and F12 keys. On the Boot Menu, use the directional arrow keys to select your flash drive. Press “Enter” to boot from the flash drive.
- Contrary to its name, the Windows 7 USB/DVD Download Tool fully supports Windows 8.1 ISO images.