Here's how to create a bootable Windows installation USB drive starting with a Windows .iso file or a Windows Setup DVD.
What you need
- Windows 10 install .iso or DVD
- USB flash drive with at least 5GB free space. This drive will be formatted, so make sure it doesn't have any important files on it.
- Technician PC - Windows PC that you'll use to format the USB flash drive
- Destination PC - A PC that you'll install Windows on
Step 1 - Format the drive and set the primary partition as active
- Connect the USB flash drive to your technician PC.
- Open Disk Management: Right-click on Start and choose Disk Management.
- Format the partition: Right-click the USB drive partition and choose Format. Select the FAT32 file system to be able to boot either BIOS-based or UEFI-based PCs.
- Set the partition as active: Right-click the USB drive partition and click Mark Partition as Active.
Step 2 - Copy Windows Setup to the USB flash drive
- Use File Explorer to copy and paste the entire contents of the Windows product DVD or ISO to the USB flash drive.
- Optional: add an unattend file to automate the installation process. For more information, see Automate Windows Setup.
Step 3 - Install Windows to the new PC
- Connect the USB flash drive to a new PC.
- Turn on the PC and press the key that opens the boot-device selection menu for the computer, such as the Esc/F10/F12 keys. Select the option that boots the PC from the USB flash drive.Windows Setup starts. Follow the instructions to install Windows.
3. Remove the USB flash drive.
Troubleshooting: file copy fails
This can happen when the Windows image file is over the FAT32 file size limit of 4GB. When this happens:
- Copy everything except the Windows image file (sources\install.wim) to the USB drive (either drag and drop, or use this command, where D: is the mounted ISO and E: is the USB flash drive.)
robocopy D: E: /s /max:3800000000
- Split the Windows image file into smaller files, and put the smaller files onto the USB drive:
Dism /Split-Image /ImageFile:D:\sources\install.wim /SWMFile:E:\sources\install.swm /FileSize:3800Note, Windows Setup automatically installs from this file, so long as you name it install.swm.