WIMUtil (Windows Installation Media Utility) is a tool I built to simplify creating custom Windows installation media. It automates adding answer files like UnattendedWinstall, extracting system drivers, and building bootable ISO files — all from a simple wizard interface. The standalone PowerShell version has been discontinued and is now fully integrated into Winhance with a modern GUI.
Applies to: Windows 10 (22H2) and Windows 11 (23H2, 24H2, 25H2) | Last updated: April 10, 2026
Important Update: The standalone PowerShell version of WIMUtil has been discontinued. All of its functionality is now built into Winhance, my Windows Enhancement Utility, with a modern graphical interface and more features. I recommend using Winhance instead of the standalone script unless you specifically need the old version.
Key Takeaways
- WIMUtil is a wizard-based utility that creates custom Windows 10 and 11 installation media from a standard Microsoft ISO file.
- It can automatically download and embed the latest UnattendedWinstall answer file, or you can add your own custom
autounattend.xml. - The driver export feature extracts all drivers from your current system and injects them into the installation media — useful when reinstalling on the same hardware.
- The standalone PowerShell version is discontinued — WIMUtil is now part of Winhance with a modern GUI and additional features.
Quick Steps (Standalone Version)
- Open PowerShell or Windows Terminal as Administrator.
- Run:
irm "https://github.com/memstechtips/WIMUtil/raw/main/src/WIMUtil.ps1" | iex - Select your Windows ISO file (or download one from Microsoft through the wizard).
- Optionally add an answer file (UnattendedWinstall or custom) and export system drivers.
- Click Create ISO to build your custom Windows installation media.
What Does WIMUtil Do?
Creating custom Windows installation media normally involves multiple tools and manual file manipulation. WIMUtil wraps the entire process into a four-step wizard that handles ISO extraction, answer file injection, driver export, and ISO creation using Microsoft’s own OSCDImg tool. I built it primarily to make using UnattendedWinstall easier — instead of manually copying files into an ISO, WIMUtil does it with a few clicks.
The utility uses a working directory at C:\WIMUtil\ where it extracts the ISO contents, adds your answer file and drivers, then repackages everything into a new bootable ISO. After creation, it offers to clean up the working directory to free disk space.
How to Launch WIMUtil
Right-click the Start button and select Windows Terminal (Admin) or Windows PowerShell (Admin). Click Yes on the UAC prompt, then paste and run this command:
irm "https://github.com/memstechtips/WIMUtil/raw/main/src/WIMUtil.ps1" | iexThis downloads and executes the WIMUtil script directly from GitHub. The wizard GUI opens in a separate window. Keep the PowerShell window running in the background — closing it will also close the wizard.
How to Create a Custom Windows ISO with WIMUtil
Step 1: Select the Windows ISO
Click Select ISO in the wizard and browse to your Windows ISO file. WIMUtil extracts the contents to C:\WIMUtil\ as the working directory. If you do not have an ISO yet, the wizard has buttons to open the Microsoft download pages for Windows 10 and Windows 11 directly.
Step 2: Add an Answer File (Optional)
On the next screen, you have two options. Click Download Latest UnattendedWinstall to automatically fetch and add the latest UnattendedWinstall answer file, or click Select File to browse to your own custom autounattend.xml. The file must be named autounattend.xml — unattend.xml files serve a different purpose and are not supported here.
You can also skip this step entirely if you just want a clean ISO without any answer file automation.
Step 3: Add Drivers (Optional)
Click Add Drivers to export all drivers from your current Windows installation into the working directory at C:\WIMUtil\$WinpeDriver$\. This is useful when you are reinstalling Windows on the same hardware — your network, storage, and peripheral drivers will be included in the installation media so Windows can find them during setup.
Tip: If you plan to test the ISO in a virtual machine, skip the driver export or delete the exported driver folder before creating the ISO. The drivers from your physical machine are not compatible with the VM and can cause the installation to fail.
Step 4: Create the ISO
On the final screen, click Get OSCDImg if the status message says the tool is not found. This downloads Microsoft’s ISO creation utility (OSCDImg.exe) from the WIMUtil GitHub repository and verifies its digital signature. Once it is ready, click Select Location to choose where to save the new ISO file, then click Create ISO.
You can monitor the progress in the PowerShell window running in the background. Once complete, the wizard confirms the ISO was saved successfully. Click Exit and choose Yes when asked about cleaning up the working directory — this frees the disk space used by the extracted files.
How to Test the Custom ISO
Before using the ISO on your main PC, I recommend testing it in a virtual machine first. Open VMware Workstation (or any VM platform), create a new virtual machine, and point it to your custom ISO. Boot from the ISO and verify that the installation runs correctly — if you included the UnattendedWinstall answer file, the setup commands should execute automatically during installation.
To install on a physical machine, you need to put the ISO on a bootable USB drive. I recommend using Ventoy — just copy the ISO file onto the Ventoy USB drive and boot from it. No additional formatting or burning required.
Frequently Asked Questions
Is WIMUtil still available as a standalone tool?
The standalone PowerShell script is still on GitHub and can be launched with the command shown above. However, it is no longer actively maintained. All development has moved to Winhance, which includes the same Windows Installation Media Utility functionality with a modern GUI and additional features like debloating and optimization.
Does WIMUtil require administrator access?
Yes. WIMUtil needs administrator privileges because it mounts ISO files, extracts system drivers, and uses Microsoft’s OSCDImg tool to create bootable media. Always launch PowerShell or Windows Terminal with Run as administrator before running the launch command.
Can I use WIMUtil to create Windows 10 installation media?
Yes. WIMUtil works with both Windows 10 and Windows 11 ISO files. Select the corresponding ISO in Step 1, and the rest of the process is identical. The UnattendedWinstall answer file also supports both Windows 10 and 11.
What is OSCDImg and why does WIMUtil need it?
OSCDImg (Operating System CD Image) is a command-line tool from Microsoft used to create bootable ISO files. It is part of the Windows Assessment and Deployment Kit (ADK). WIMUtil downloads it automatically if it is not already on your system, and verifies the file hash and digital signature to confirm it is the genuine Microsoft tool.
Will the exported drivers cause issues if I install on different hardware?
They can. The driver export feature copies drivers from your current system, so they are specific to your hardware. If you install the ISO on a different machine or a virtual machine, the mismatched drivers may cause setup failures. Skip the driver export step or delete the $WinpeDriver$ folder from the working directory before creating the ISO if you plan to use it on different hardware.
signature date mismatch wont download oscdimg date is out by 1 hr
Tried using the manual download script WIMUtil.ps1 by setting the date / time myself but my pc wont allow the script to run even as powershell admin??
Can you try again? I removed that signature date mismatch check from the utility, it shouldn’t check for that anymore.
Thank you for all your hard work.
Thank you kindly.
Good tutorial.
Wonderful cool mod.
Cheers m8.
Hello, first of all, it is a realy nice tool.
I build an image and used it allready several times for the reinstalation on several PC ´s and Notebooks. And so far it works fine.
But now ihave the Problem that even when allowing Remotedesktop i cant use it betwean PC `s with this installation. When i try to conect RDP tells me that its not posible to astablish an connection with the user credencials, but with an “normal” Win11 instalation it works with the same cedancials.
Hey there and thanks. Was this with the PowerShell version of WIMUtil or the new version in Winhance? I suggest that you create an issue on the Winhance GitHub page with more information so I can take a closer look.