WIMUtil, short for Windows Installation Media Utility is designed to help optimize and customize Windows Installation Media, streamlining your Windows installs. In this post, I’ll walk you through a live test of WIMUtil, showcase how it works, and create a custom Windows ISO that we’ll test in a virtual machine. Whether you’re looking to simplify Windows installations or leverage tools like UnattendedWinstall, this guide will help you get started.
Key Takeaways
- WIMUtil is a streamlined tool for customizing Windows installation media, making tasks like adding drivers and answer files simple.
- You can create a bootable ISO tailored to your needs, including custom setups with UnattendedWinstall.
- This guide includes step-by-step instructions to test the utility using a virtual machine.
Requirements
Before you begin, make sure you have the following:
- Windows ISO File: Download from Microsoft’s official site or use an existing ISO.
- Guides: Download Windows 10 – Download Windows 11
- WIMUtil: Launch command also available on GitHub
- Administrator Access: Launch PowerShell or Windows Terminal with admin rights.
- Optional: VMware or another virtual machine platform for testing.
- Optional: Ventoy for creating a bootable USB Flash Drive
Why Use WIMUtil?
Creating custom Windows installation media can be complex. WIMUtil simplifies the process by automating tasks like:
- Adding answer files for unattended installations.
- Extracting drivers from your system.
- Streamlining the creation of bootable ISO files.
Whether you’re preparing for a clean installation or deploying on multiple machines, WIMUtil saves time and reduces errors.
How to Use WIMUtil
Step 1: Launching WIMUtil
Open PowerShell as Administrator:
- Windows 10/11: Right-click on the Start button and select Windows PowerShell (Admin) or Windows Terminal (Admin).
- PowerShell will open in a new window.
Confirm Administrator Privileges:
- If prompted by the User Account Control (UAC), click Yes to allow PowerShell to run as an administrator.
Paste and Run the Command:
- Copy the following command:
irm "https://github.com/memstechtips/WIMUtil/raw/main/src/WIMUtil.ps1" | iex - To paste into PowerShell:
- Right-click in the PowerShell or Terminal window, or
- Press Ctrl + V.
- The copied command will be pasted automatically.
- Press Enter to execute the command.
Step 2: Selecting the Windows ISO
- Click on Select ISO in the WIMUtil wizard.
- Choose the ISO file from your computer. If you don’t have one, use the built-in buttons to download Windows 10 or 11 ISOs from Microsoft.
If you have any trouble downloading the ISO Files, please see these guides:
Step 3: Adding an Answer File
- Choose between:
- Downloading the latest UnattendedWinstall file.
- Uploading your custom
autounattend.xmlfile.
- Ensure the file type is correct; only
autounattend.xmlfiles are supported.
Step 4: Adding Drivers
- Export drivers from your current system by selecting Add Drivers.
- The drivers will be saved in the working directory
C:\WIMUtil\$WinpeDriver$. - For virtual machine setups, delete unnecessary drivers to avoid installation issues.
Step 5: Creating the Custom ISO
- Click Get OSCDImage to download Microsoft’s tool if it’s not already available on your system.
- Select a save location for the new ISO and name the file.
- Click Create ISO and monitor progress in the terminal.
Step 6: Using the ISO File to Install Windows
Testing the ISO in a Virtual Machine
Once your custom ISO file is ready, you can test it by installing Windows in a virtual machine. This is a great way to ensure everything works as expected before using it on a physical device.
Using the ISO in a Virtual Machine
- Open VMware or another virtualization tool.
- Create a new virtual machine and select the custom ISO you created with WIMUtil.
- Follow the installation steps. The UnattendedWinstall script should execute automatically if you added it to the installation media.
Using Ventoy to Create Bootable Media
If you want to use the ISO for installing Windows on a physical device, you’ll need to create bootable media. I highly recommend using Ventoy, a user-friendly tool for this purpose.
Steps to Use Ventoy
- Download and run Ventoy2Disk.exe which can be found on the official Ventoy GitHub page.
- Format your USB drive using Ventoy (make sure to back up any important data first).
- Copy the ISO file directly to the USB drive—no additional setup is needed.
- Boot from the USB flash drive on your target device and select your ISO.
- Follow the steps to install Windows.
For a detailed guide, check out my Ventoy setup tutorial.
Conclusion
WIMUtil helps tremendously in successfully creating a customized Windows ISO file. With features like built-in support for adding answer files such as the UnattendedWinstall autounattend.xml file and device driver integration, it’s a valuable tool for anyone managing Windows installations.
Frequently Asked Questions (FAQ)
What is WIMUtil?
WIMUtil is a utility for customizing Windows installation media, allowing users to add answer files, drivers, and create ISO files.
Can I use WIMUtil without admin rights?
No, administrative access is required to run WIMUtil and perform system-level tasks.
Does WIMUtil support older Windows versions?
Currently, WIMUtil focuses on Windows 10 and 11. For older versions, alternative tools may be required.
Is WIMUtil compatible with all virtualization platforms?
Yes, as long as the platform supports booting from ISO files, you can use WIMUtil-created ISOs.
Where can I download UnattendedWinstall?
UnattendedWinstall is integrated into WIMUtil for easy access, but you can also download it directly from the Github project page.
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.