Win32 Disk Imager offers a reliable Windows utility for writing raw disk image files to USB drives and removable storage media. Simplify bootable device preparation, image restoration, and storage management through an intuitive imaging experience built for precision and performance.
Win32 Disk Imager is a small Windows program that copies a disk image onto removable media, or copies removable media into a disk image, one sector at a time. It doesn't care what file system is on the card: FAT32, ext4, a hidden boot partition, even data Windows can't read at all goes across exactly as it is.
That is why it became the standard answer for single-board computer users, embedded developers and anyone restoring firmware cards. Most operating system images for small boards ship as a raw .img, and Windows Explorer can't put one onto a card. Copying the file onto the card just leaves a file sitting on it. Win32 Disk Imager opens the physical device directly and lays the image down from sector 0 onward, partition table included.
The original project is maintained on SourceForge and built with Qt; its 1.0 release added Verify Only, SHA-1 and SHA-256 hashes and the Read Only Allocated Partitions option. The GitHub source offered on this site is a native Win32 rewrite of the same tool. It keeps the interface and features, drops the Qt runtime so the executable is very small, runs as far back as Windows XP, and can target either a whole USB device or a single partition on it.
Think of it as a photocopier for storage media. It copies every byte exactly as it is, including the parts Windows can't see.
Win32 Disk Imager Properties
There are no wizards, no account and no background service. Each control in the window does one job, and the result lands either as a file on your PC or as a raw copy on the device.
Verify compares the image file against the device byte by byte and reports the first mismatch. It reads only as much of the card as the image covers, so checking a 2 GB image on a 32 GB card takes as long as 2 GB, not 32. Run it after every write you care about. A fake-capacity card or a tired reader will usually show up here before it shows up as a corrupt boot.
Lays a raw image onto an SD card or USB stick from sector 0, partition table and boot code included.
Turns a working card into a .img file you can archive, duplicate or restore after an update goes wrong.
Generate MD5, SHA-1 or SHA-256 for the selected file and compare it with the checksum the publisher lists.
Reads to the end of the last defined partition, so a 4 GB system on a 64 GB card gives you a 4 GB backup.
The native build can target a whole USB device or one partition on it, and shows the size of each.
No Qt runtime in the native fork. It is a single small executable that starts instantly, even from a USB stick.
The last image folder is kept between sessions, so repeat flashing is just Browse, Write, done.
Only removable media appear in the Device box, which keeps your system drive out of reach by default.
Behind the five buttons there is one simple loop. Windows locks the volume, the program streams fixed-size sector blocks between your file and the physical device, and then it releases the lock so Windows can mount the result.
An uncompressed .img on your PC. Its size sets how many sectors get written.
Opened as \\.\PhysicalDriveN after its volume is locked and dismounted.
Copies every sector, or only up to the last partition, into a new image at the path you typed.
Overwrites the card from sector 0. Whatever was on it before is gone, partition table included.
Reads the device back and compares it with the image. It changes nothing and is safe to repeat.
Calculates MD5, SHA-1 or SHA-256 of the image so you can match it against the published value.
The download below is the source archive of the native Win32 build. Building it takes one Visual Studio session. If you'd rather not compile anything, the original installer is still published on the SourceForge project page.
Use the download button further down this page. It fetches Win32DiskImager-master.zip straight from the GitHub repository, which is the current state of the master branch.
C:\src\. Deep paths inside Downloads can trip older build tools.github.com/znone/.Right-click the ZIP, choose Extract All, and open the new Win32DiskImager-master folder. The README lists exactly what the build expects: Visual Studio 2010 or later, the WTL library and the Windows SDK 7.0.
Install Visual Studio (Community edition is fine) with the Desktop development with C++ workload. Then add WTL. The simplest route is the wtl NuGet package; alternatively, download WTL and add its Include folder to the project's include directories.
Open the solution file from the extracted folder. If Visual Studio offers to retarget the project to your installed SDK and toolset, accept. Pick Release and Win32, then choose Build → Build Solution.
.exe lands in the Release output folder and needs no installer.atlapp.h error means WTL isn't on the include path yet.Double-click the executable and accept the UAC prompt, because raw device access needs administrator rights. A binary downloaded from elsewhere may trigger a SmartScreen notice. Choose More info → Run anyway only if it came from the official repository or project page.
.img.The tool is narrow on purpose. These four jobs account for nearly every time people reach for it.
Write Linux distributions, media-centre builds and retro-gaming images to microSD for small ARM boards, then verify before the first boot.
Read a configured card into a dated .img before an upgrade. If the update breaks something, write the image back and you're where you started.
Prepare one master card, read it once, then write identical copies for kiosks, sensors, classrooms or a stack of test devices.
Write recovery images for routers, 3D printers and industrial controllers, or hybrid Linux images that boot straight from a USB stick.
This is the native Win32 edition: the same Read, Write, Verify and hash workflow, rewritten without Qt so the program stays very small and also runs on older Windows. The archive contains source code. Build it once with the steps above and keep the executable wherever you like.
Download ZIPmaster branch · from GitHubWant a prebuilt installer instead? The original 1.0.0 release is on the official SourceForge project page. The repository page shows commit history and issues.
The native fork goes back to Windows XP. The Qt 1.0 build runs on Windows 7 and later. On Windows on ARM devices, the 32-bit executable runs under emulation.
| Capability | Win32 Disk Imager | Rufus | balenaEtcher | Raspberry Pi Imager |
|---|---|---|---|---|
| Write raw .img | Yes | Yes (DD mode) | Yes | Yes |
| Read card to image | Yes, full or allocated | Partial, VHD/VHDX | No | No |
| Hash tools | MD5 · SHA-1 · SHA-256 | Yes, image checksums | No | No |
| Verification | On demand | Bad-block scan | Automatic | Automatic |
| Compressed images | Extract first | Yes | Yes | Yes |
| Windows install USB | No | Yes | No | No |
| Platforms | Windows | Windows | Windows, macOS, Linux | Windows, macOS, Linux |
These six problems cover most failed sessions. Pick an entry to see the likely cause and the fix, in the order worth trying.
The window never appears, flashes and closes, or Task Manager shows the process as not responding. Startup is when the tool checks every drive letter, so a slow or stuck drive holds it up.
Windows refused the exclusive lock the program needs on the volume. Usually something else has the card open: an Explorer window, a preview pane, an antivirus scan or a backup client.
The Device box lists only removable media that have a drive letter. Card readers without media, cards with no recognised partition, and USB drives that report themselves as fixed disks don't appear.
diskmgmt.msc) and confirm the card is visible.The image is larger than the target. Cards sold as the same size differ by a few hundred megabytes, so an image read from one brand's 16 GB card can be too large for another brand's.
Nothing is broken. Linux images usually contain a small FAT boot partition and a large ext4 partition that Windows can't read, so Explorer shows only the small one and may offer to format the rest. Say no.
diskpart → list disk → select disk N → clean does the same. Check N carefully, because selecting the wrong disk erases it.Either the image was corrupted in transit or the card isn't storing what it was sent. Fake-capacity cards accept data past their real size and silently lose it.
The program itself barely registers. What you actually need is free space for images and a card reader you trust.
XP → 11, 32- or 64-bit
256 MB+ free; the tool uses very little
SD / USB via a working reader
Administrator for raw access
There is no undo after Write. These four habits keep a routine flash from wiping the wrong drive.
Unplug every other USB drive first. If you aren't sure which letter the card has, eject it and watch which one disappears.
Compare the image's SHA-256 with the value its publisher lists. A mismatch means a corrupted or altered download.
If the card holds anything you might want later, Read it to an image first. Storage is cheap; rebuilding a setup isn't.
Get the program from its repository or project page, and only copy images you created or are licensed to use.
Short answers here. The guides go deeper on portable use, each Windows version, alternatives and launch problems.
Yes. It is open-source software under the GNU GPL v2 licence. There is no paid tier, trial or account, and you are free to read, build and share the source.
It writes raw data, so hybrid ISOs, which most Linux distributions ship, work once you pick the file. In the file dialog, change the filter to all files, or rename a copy to .img. Standard Windows installation ISOs are not hybrid and won't boot this way; use a dedicated installer tool for those.
The native Win32 build is a single executable with no installer and no runtime, so it is portable by nature. You can run it from a USB stick. The SourceForge release also offers a binary ZIP alongside the installer.
Yes. Both the native fork and the 1.0 release run on Windows 11, including on recent feature updates. Run it as administrator, and close Explorer windows showing the card before you write.
The SourceForge project is the original Qt-based program, last released as 1.0.0. The GitHub source is a native Win32 rewrite with the same interface and features. It is much smaller, runs on Windows XP, and can work on a whole USB device or on a single partition.
Yes. Type a new file name into Image File, choose the card under Device and press Read. Tick Read Only Allocated Partitions if you don't want empty space included, then hash the result so you can check it later.
Windows only shows partitions it can read. A Linux image leaves a small FAT boot partition visible and a large ext4 partition hidden. The space isn't lost; delete the partitions in Disk Management to reclaim it.
No, it is Windows-only. On Linux and macOS the built-in dd command does the same raw copy, and graphical tools such as balenaEtcher cover the flashing side.
No. Writing replaces everything on the card, including the partition layout. To turn a flashed card back into normal storage, delete its partitions in Disk Management and format it there.
Opening a physical disk and locking its volume are privileged operations in Windows. Without elevation the program can't see or write the device, so it asks for UAC approval at launch.