Win32 Disk Imager

Win32 Disk Imager is a free, open source tool for writing disk image files (IMG, ISO) to USB flash drives and SD cards. It also reads removable media back into image files for backup. Licensed under GPLv2. Windows only.

What it does

The interface has two main functions: Write and Read. To flash an image to a USB drive or SD card, click the folder icon to select your IMG or ISO file, choose the target drive letter from the Device dropdown, confirm you picked the right drive, and click Write. The program overwrites the entire drive with the image contents. To create a backup, select the drive letter and specify an output file path, then click Read - this copies the full drive contents into an IMG file on your hard disk.

The Device dropdown only shows removable drives, which prevents you from accidentally overwriting your system disk. A Verify option compares the written data against the source file to confirm the write was successful. The tool is commonly used for flashing Raspberry Pi operating system images to SD cards and creating bootable Linux USB drives.

Who it is for

I use Win32 Disk Imager specifically for Raspberry Pi SD cards because it does exactly one thing and does it without confusion. If you need more features like partition scheme selection or Windows 11 bypass, Rufus is the better choice. Balena Etcher is another alternative with a more modern interface. But for straightforward image writing with backup capability, Win32 Disk Imager is as simple as it gets.